{"id":4856,"date":"2026-09-23T09:00:00","date_gmt":"2026-09-23T09:00:00","guid":{"rendered":"https:\/\/otus.ru\/journal\/?p=4856"},"modified":"2026-09-25T15:34:41","modified_gmt":"2026-09-25T15:34:41","slug":"pishem-sobstvennyj-kalkulyator-na-si","status":"publish","type":"post","link":"https:\/\/otus.ru\/journal\/pishem-sobstvennyj-kalkulyator-na-si\/","title":{"rendered":"\u041a\u0430\u043b\u044c\u043a\u0443\u043b\u044f\u0442\u043e\u0440 \u043d\u0430 C: \u043f\u0438\u0448\u0435\u043c \u043a\u043e\u043d\u0441\u043e\u043b\u044c\u043d\u0443\u044e \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u0443 \u0441 \u043f\u0440\u043e\u0432\u0435\u0440\u043a\u043e\u0439 \u0432\u0432\u043e\u0434\u0430"},"content":{"rendered":"

\u041a\u043e\u043d\u0441\u043e\u043b\u044c\u043d\u044b\u0439 \u043a\u0430\u043b\u044c\u043a\u0443\u043b\u044f\u0442\u043e\u0440 \u043d\u0430 C<\/strong> — \u044d\u0442\u043e \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u0430, \u043a\u043e\u0442\u043e\u0440\u0430\u044f \u0447\u0438\u0442\u0430\u0435\u0442 \u0434\u0432\u0430 \u0447\u0438\u0441\u043b\u0430 \u0438 \u0437\u043d\u0430\u043a \u043e\u043f\u0435\u0440\u0430\u0446\u0438\u0438, \u0432\u044b\u0431\u0438\u0440\u0430\u0435\u0442 \u0434\u0435\u0439\u0441\u0442\u0432\u0438\u0435 \u043e\u043f\u0435\u0440\u0430\u0442\u043e\u0440\u043e\u043c switch<\/code> \u0438 \u043f\u0435\u0447\u0430\u0442\u0430\u0435\u0442 \u0440\u0435\u0437\u0443\u043b\u044c\u0442\u0430\u0442. \u0417\u0430\u0434\u0430\u0447\u0430 \u0443\u0447\u0435\u0431\u043d\u0430\u044f, \u043d\u043e \u043d\u0430 \u043d\u0435\u0439 \u0432\u0438\u0434\u043d\u044b \u0442\u0440\u0438 \u0432\u0435\u0449\u0438, \u043d\u0430 \u043a\u043e\u0442\u043e\u0440\u044b\u0445 \u0441\u043f\u043e\u0442\u044b\u043a\u0430\u044e\u0442\u0441\u044f \u043d\u043e\u0432\u0438\u0447\u043a\u0438: \u043f\u0440\u043e\u0432\u0435\u0440\u043a\u0430 \u0442\u043e\u0433\u043e, \u0447\u0442\u043e scanf<\/code> \u0434\u0435\u0439\u0441\u0442\u0432\u0438\u0442\u0435\u043b\u044c\u043d\u043e \u043f\u0440\u043e\u0447\u0438\u0442\u0430\u043b \u0432\u0432\u043e\u0434, \u0437\u0430\u0431\u044b\u0442\u044b\u0439 break<\/code> \u0438 \u0434\u0435\u043b\u0435\u043d\u0438\u0435 \u043d\u0430 \u043d\u043e\u043b\u044c.<\/p>\n

\n

\u0421\u043e\u0434\u0435\u0440\u0436\u0430\u043d\u0438\u0435<\/strong><\/p>\n

    \n
  1. \u041f\u043e\u043b\u043d\u0430\u044f \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u0430: \u043e\u0434\u043d\u043e \u0432\u044b\u0440\u0430\u0436\u0435\u043d\u0438\u0435<\/a><\/li>\n
  2. \u0420\u0430\u0437\u0431\u043e\u0440 \u043f\u043e \u0441\u0442\u0440\u043e\u043a\u0430\u043c<\/a><\/li>\n
  3. \u0422\u0438\u043f\u0438\u0447\u043d\u044b\u0435 \u043e\u0448\u0438\u0431\u043a\u0438: \u043a\u043e\u0434 -> \u0440\u0435\u0437\u0443\u043b\u044c\u0442\u0430\u0442 -> \u0438\u0441\u043f\u0440\u0430\u0432\u043b\u0435\u043d\u0438\u0435<\/a><\/li>\n
  4. \u041a\u0430\u043b\u044c\u043a\u0443\u043b\u044f\u0442\u043e\u0440 \u0432 \u0446\u0438\u043a\u043b\u0435 \u0441 \u0443\u0441\u0442\u043e\u0439\u0447\u0438\u0432\u044b\u043c \u0432\u0432\u043e\u0434\u043e\u043c<\/a><\/li>\n
  5. \u0420\u0430\u0441\u0448\u0438\u0440\u0435\u043d\u0438\u0435: \u0432\u044b\u0440\u0430\u0436\u0435\u043d\u0438\u044f \u0441\u043e \u0441\u043a\u043e\u0431\u043a\u0430\u043c\u0438<\/a><\/li>\n
  6. \u0415\u0441\u043b\u0438 \u043d\u0435 \u043f\u043e\u043b\u0443\u0447\u0438\u043b\u043e\u0441\u044c<\/a><\/li>\n
  7. \u0412\u044b\u0432\u043e\u0434\u044b<\/a><\/li>\n
  8. \u0413\u0434\u0435 \u043f\u0440\u0438\u043c\u0435\u043d\u044f\u0435\u0442\u0441\u044f \/ \u0441\u0432\u044f\u0437\u044c \u0441 \u043f\u0440\u0430\u043a\u0442\u0438\u043a\u043e\u0439<\/a><\/li>\n
  9. FAQ<\/a><\/li>\n<\/ol>\n<\/div>\n

    \u041d\u0438\u0436\u0435 — \u0433\u043e\u0442\u043e\u0432\u0430\u044f \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u0430 \u0446\u0435\u043b\u0438\u043a\u043e\u043c, \u0440\u0430\u0437\u0431\u043e\u0440 \u043f\u043e \u0441\u0442\u0440\u043e\u043a\u0430\u043c, \u0442\u0438\u043f\u0438\u0447\u043d\u044b\u0435 \u043e\u0448\u0438\u0431\u043a\u0438 \u0441 \u0440\u0435\u0430\u043b\u044c\u043d\u044b\u043c \u0432\u044b\u0432\u043e\u0434\u043e\u043c, \u0432\u0435\u0440\u0441\u0438\u044f \u0441 \u0446\u0438\u043a\u043b\u043e\u043c \u0438 \u0440\u0430\u0441\u0448\u0438\u0440\u0435\u043d\u0438\u0435 \u0434\u043e \u0432\u044b\u0440\u0430\u0436\u0435\u043d\u0438\u0439 \u0441\u043e \u0441\u043a\u043e\u0431\u043a\u0430\u043c\u0438 \u0432\u0440\u043e\u0434\u0435 (2 + 3) * 4<\/code>. \u0412\u0441\u0435 \u043f\u0440\u0438\u043c\u0435\u0440\u044b \u0441\u043a\u043e\u043c\u043f\u0438\u043b\u0438\u0440\u043e\u0432\u0430\u043d\u044b \u0438 \u0437\u0430\u043f\u0443\u0449\u0435\u043d\u044b \u043d\u0430 Apple clang 21 (macOS, arm64) \u0438 GCC 13.3 (Ubuntu 24.04) \u0441 \u0444\u043b\u0430\u0433\u0430\u043c\u0438 -std=c17 -Wall -Wextra<\/code>, \u043f\u0440\u043e\u0432\u0435\u0440\u043a\u0430 23.09.2026; \u043a\u043e\u0434 \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u0443\u0435\u0442 \u0442\u043e\u043b\u044c\u043a\u043e \u0441\u0442\u0430\u043d\u0434\u0430\u0440\u0442\u043d\u0443\u044e \u0431\u0438\u0431\u043b\u0438\u043e\u0442\u0435\u043a\u0443 C \u0438 \u043d\u0435 \u0437\u0430\u0432\u0438\u0441\u0438\u0442 \u043e\u0442 \u041e\u0421.<\/p>\n

    \u041f\u043e\u043b\u043d\u0430\u044f \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u0430: \u043e\u0434\u043d\u043e \u0432\u044b\u0440\u0430\u0436\u0435\u043d\u0438\u0435<\/h2>\n
    #include<\/span> <\/span><stdio.h><\/span>\n\nint<\/span> <\/span>main<\/span>(<\/span>void<\/span>) {<\/span>\n    <\/span>double<\/span> <\/span>a<\/span>, <\/span>b<\/span>;<\/span>\n    <\/span>char<\/span> <\/span>op<\/span>;<\/span>\n\n    <\/span>printf<\/span>(<\/span>\"\u0412\u0432\u0435\u0434\u0438\u0442\u0435 \u0432\u044b\u0440\u0430\u0436\u0435\u043d\u0438\u0435, \u043d\u0430\u043f\u0440\u0438\u043c\u0435\u0440 7 \/ 2: \"<\/span>);<\/span>\n    <\/span>if<\/span> (<\/span>scanf<\/span>(<\/span>\"%lf %c %lf\"<\/span>, <\/span>&<\/span>a<\/span>, <\/span>&<\/span>op<\/span>, <\/span>&<\/span>b<\/span>) <\/span>!=<\/span> <\/span>3<\/span>) {<\/span>\n        <\/span>printf<\/span>(<\/span>\"\u041e\u0448\u0438\u0431\u043a\u0430: \u043d\u0443\u0436\u043d\u043e \u0447\u0438\u0441\u043b\u043e, \u0437\u043d\u0430\u043a \u0438 \u0447\u0438\u0441\u043b\u043e\\n\"<\/span>);<\/span>\n        <\/span>return<\/span> <\/span>1<\/span>;<\/span>\n    }<\/span>\n\n    <\/span>switch<\/span> (<\/span>op<\/span>) {<\/span>\n    <\/span>case<\/span> <\/span>'+'<\/span>:<\/span>\n        <\/span>printf<\/span>(<\/span>\"%g\\n\"<\/span>, <\/span>a<\/span> <\/span>+<\/span> <\/span>b<\/span>);<\/span>\n        <\/span>break<\/span>;<\/span>\n    <\/span>case<\/span> <\/span>'-'<\/span>:<\/span>\n        <\/span>printf<\/span>(<\/span>\"%g\\n\"<\/span>, <\/span>a<\/span> <\/span>-<\/span> <\/span>b<\/span>);<\/span>\n        <\/span>break<\/span>;<\/span>\n    <\/span>case<\/span> <\/span>'*'<\/span>:<\/span>\n        <\/span>printf<\/span>(<\/span>\"%g\\n\"<\/span>, <\/span>a<\/span> <\/span>*<\/span> <\/span>b<\/span>);<\/span>\n        <\/span>break<\/span>;<\/span>\n    <\/span>case<\/span> <\/span>'\/'<\/span>:<\/span>\n        <\/span>if<\/span> (<\/span>b<\/span> <\/span>==<\/span> <\/span>0<\/span>) {<\/span>\n            <\/span>printf<\/span>(<\/span>\"\u041e\u0448\u0438\u0431\u043a\u0430: \u0434\u0435\u043b\u0435\u043d\u0438\u0435 \u043d\u0430 \u043d\u043e\u043b\u044c\\n\"<\/span>);<\/span>\n            <\/span>return<\/span> <\/span>1<\/span>;<\/span>\n        }<\/span>\n        <\/span>printf<\/span>(<\/span>\"%g\\n\"<\/span>, <\/span>a<\/span> <\/span>\/<\/span> <\/span>b<\/span>);<\/span>\n        <\/span>break<\/span>;<\/span>\n    <\/span>default<\/span>:<\/span>\n        <\/span>printf<\/span>(<\/span>\"\u041e\u0448\u0438\u0431\u043a\u0430: \u043d\u0435\u0438\u0437\u0432\u0435\u0441\u0442\u043d\u0430\u044f \u043e\u043f\u0435\u0440\u0430\u0446\u0438\u044f '%c'\\n\"<\/span>, <\/span>op<\/span>);<\/span>\n        <\/span>return<\/span> <\/span>1<\/span>;<\/span>\n    }<\/span>\n    <\/span>return<\/span> <\/span>0<\/span>;<\/span>\n}<\/span><\/code><\/pre>\n
    \u0421\u043e\u0445\u0440\u0430\u043d\u0438\u0442\u0435 \u043a\u043e\u0434 \u0432 calc.c<\/code>, \u0441\u043e\u0431\u0435\u0440\u0438\u0442\u0435 \u0438 \u0437\u0430\u043f\u0443\u0441\u0442\u0438\u0442\u0435:<\/p>\n
    cc <\/span>-std=<\/span>c17 <\/span>-Wall <\/span>-Wextra <\/span>-o <\/span>calc <\/span>calc.c\n.\/calc<\/code><\/pre>\n
    \u0420\u0435\u0437\u0443\u043b\u044c\u0442\u0430\u0442\u044b \u043f\u0440\u043e\u0433\u043e\u043d\u0430 (\u0432\u0432\u043e\u0434 -> \u043e\u0442\u0432\u0435\u0442 \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u044b, \u0432 \u0441\u043a\u043e\u0431\u043a\u0430\u0445 \u043a\u043e\u0434 \u0432\u043e\u0437\u0432\u0440\u0430\u0442\u0430):<\/p>\n
    7 \/ 2    -> 3.5                                  (0)\n7\/2      -> 3.5                                  (0)\n2.5 * 4  -> 10                                   (0)\n5 \/ 0    -> \u041e\u0448\u0438\u0431\u043a\u0430: \u0434\u0435\u043b\u0435\u043d\u0438\u0435 \u043d\u0430 \u043d\u043e\u043b\u044c              (1)\n3 % 2    -> \u041e\u0448\u0438\u0431\u043a\u0430: \u043d\u0435\u0438\u0437\u0432\u0435\u0441\u0442\u043d\u0430\u044f \u043e\u043f\u0435\u0440\u0430\u0446\u0438\u044f '%'     (1)\nabc      -> \u041e\u0448\u0438\u0431\u043a\u0430: \u043d\u0443\u0436\u043d\u043e \u0447\u0438\u0441\u043b\u043e, \u0437\u043d\u0430\u043a \u0438 \u0447\u0438\u0441\u043b\u043e    (1)\n<\/code><\/pre>\n
    \u0420\u0430\u0437\u0431\u043e\u0440 \u043f\u043e \u0441\u0442\u0440\u043e\u043a\u0430\u043c<\/h2>\n
    \u0422\u0438\u043f double<\/code>, \u0430 \u043d\u0435 int<\/code>.<\/strong> \u041a\u0430\u043b\u044c\u043a\u0443\u043b\u044f\u0442\u043e\u0440 \u0434\u043e\u043b\u0436\u0435\u043d \u0443\u043c\u0435\u0442\u044c 7 \/ 2 = 3.5. \u0415\u0441\u043b\u0438 \u043e\u0431\u044a\u044f\u0432\u0438\u0442\u044c \u0447\u0438\u0441\u043b\u0430 \u043a\u0430\u043a int<\/code>, \u0434\u0435\u043b\u0435\u043d\u0438\u0435 \u0441\u0442\u0430\u043d\u0435\u0442 \u0446\u0435\u043b\u043e\u0447\u0438\u0441\u043b\u0435\u043d\u043d\u044b\u043c \u0438 \u0434\u0440\u043e\u0431\u043d\u0430\u044f \u0447\u0430\u0441\u0442\u044c \u043e\u0442\u0431\u0440\u043e\u0441\u0438\u0442\u0441\u044f (\u043f\u0440\u0438\u043c\u0435\u0440 \u043d\u0438\u0436\u0435).<\/p>\n
    \u041f\u0440\u043e\u0432\u0435\u0440\u043a\u0430 scanf(...) != 3<\/code>.<\/strong> \u0424\u0443\u043d\u043a\u0446\u0438\u044f \u0432\u043e\u0437\u0432\u0440\u0430\u0449\u0430\u0435\u0442 \u0447\u0438\u0441\u043b\u043e \u0443\u0441\u043f\u0435\u0448\u043d\u043e \u043f\u0440\u043e\u0447\u0438\u0442\u0430\u043d\u043d\u044b\u0445 \u043f\u043e\u043b\u0435\u0439. \u0422\u0440\u0438 \u043f\u043e\u043b\u044f — \u0434\u0432\u0430 \u0447\u0438\u0441\u043b\u0430 \u0438 \u0437\u043d\u0430\u043a. \u041f\u0440\u0438 \u0432\u0432\u043e\u0434\u0435 \u0431\u0443\u043a\u0432 \u0432\u0435\u0440\u043d\u0435\u0442\u0441\u044f \u043c\u0435\u043d\u044c\u0448\u0435 \u0442\u0440\u0435\u0445, \u0438 \u0441\u0447\u0438\u0442\u0430\u0442\u044c \u0441 \u0442\u0430\u043a\u0438\u043c\u0438 \u043f\u0435\u0440\u0435\u043c\u0435\u043d\u043d\u044b\u043c\u0438 \u043d\u0435\u043b\u044c\u0437\u044f.<\/p>\n
    \u041f\u0440\u043e\u0431\u0435\u043b \u043f\u0435\u0440\u0435\u0434 %c<\/code> \u0432 \u0444\u043e\u0440\u043c\u0430\u0442\u0435.<\/strong> \u0421\u043f\u0435\u0446\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440 %c<\/code>, \u0432 \u043e\u0442\u043b\u0438\u0447\u0438\u0435 \u043e\u0442 %lf<\/code>, \u043d\u0435 \u043f\u0440\u043e\u043f\u0443\u0441\u043a\u0430\u0435\u0442 \u043f\u0440\u043e\u0431\u0435\u043b\u044b \u0441\u0430\u043c. \u041f\u0440\u043e\u0431\u0435\u043b \u0432 \u0441\u0442\u0440\u043e\u043a\u0435 \u0444\u043e\u0440\u043c\u0430\u0442\u0430 \u043e\u0437\u043d\u0430\u0447\u0430\u0435\u0442 \u00ab\u043f\u0440\u043e\u043f\u0443\u0441\u0442\u0438 \u043b\u044e\u0431\u044b\u0435 \u043f\u0440\u043e\u0431\u0435\u043b\u044c\u043d\u044b\u0435 \u0441\u0438\u043c\u0432\u043e\u043b\u044b\u00bb, \u043f\u043e\u044d\u0442\u043e\u043c\u0443 \u0440\u0430\u0431\u043e\u0442\u0430\u044e\u0442 \u0438 7 \/ 2<\/code>, \u0438 7\/2<\/code>.<\/p>\n
    switch<\/code> \u0438 break<\/code>.<\/strong> switch<\/code> \u0441\u0440\u0430\u0432\u043d\u0438\u0432\u0430\u0435\u0442 op<\/code> \u0441 \u043a\u0430\u0436\u0434\u043e\u0439 \u043c\u0435\u0442\u043a\u043e\u0439 case<\/code>. break<\/code> \u0432\u044b\u0445\u043e\u0434\u0438\u0442 \u0438\u0437 switch<\/code>; \u0431\u0435\u0437 \u043d\u0435\u0433\u043e \u0432\u044b\u043f\u043e\u043b\u043d\u0435\u043d\u0438\u0435 \u00ab\u043f\u0440\u043e\u0432\u0430\u043b\u0438\u0432\u0430\u0435\u0442\u0441\u044f\u00bb \u0432 \u0441\u043b\u0435\u0434\u0443\u044e\u0449\u0443\u044e \u0432\u0435\u0442\u043a\u0443. \u0412\u0435\u0442\u043a\u0430 default<\/code> \u043b\u043e\u0432\u0438\u0442 \u0432\u0441\u0435, \u0447\u0442\u043e \u043d\u0435 \u043f\u043e\u043f\u0430\u043b\u043e \u0432 case<\/code>.<\/p>\n
    %g<\/code> \u0432 printf<\/code>.<\/strong> \u041f\u0435\u0447\u0430\u0442\u0430\u0435\u0442 10<\/code>, \u0430 \u043d\u0435 10.000000<\/code>; \u043f\u043e \u0443\u043c\u043e\u043b\u0447\u0430\u043d\u0438\u044e \u0434\u043e 6 \u0437\u043d\u0430\u0447\u0430\u0449\u0438\u0445 \u0446\u0438\u0444\u0440, \u0431\u043e\u043b\u044c\u0448\u0435 \u0434\u0430\u0435\u0442 %.15g<\/code>.<\/p>\n
    \u0421\u0440\u0430\u0432\u043d\u0435\u043d\u0438\u0435 b == 0<\/code>.<\/strong> \u041a\u043e\u0440\u0440\u0435\u043a\u0442\u043d\u043e \u0434\u043b\u044f \u0432\u0432\u0435\u0434\u0435\u043d\u043d\u043e\u0433\u043e \u0434\u0435\u043b\u0438\u0442\u0435\u043b\u044f; \u0434\u043b\u044f \u0440\u0435\u0437\u0443\u043b\u044c\u0442\u0430\u0442\u043e\u0432 \u0432\u044b\u0447\u0438\u0441\u043b\u0435\u043d\u0438\u0439 \u0441 \u0434\u0440\u043e\u0431\u044f\u043c\u0438 ==<\/code> \u043d\u0435\u043d\u0430\u0434\u0435\u0436\u043d\u043e.<\/p>\n
    \u041f\u0435\u0440\u0435\u043f\u043e\u043b\u043d\u0435\u043d\u0438\u0435.<\/strong> \u041f\u0440\u043e\u0432\u0435\u0440\u043a\u0430 \u043d\u0430 \u043d\u043e\u043b\u044c \u043d\u0435 \u0441\u043f\u0430\u0441\u0430\u0435\u0442 \u043e\u0442 \u0432\u044b\u0445\u043e\u0434\u0430 \u0437\u0430 \u0434\u0438\u0430\u043f\u0430\u0437\u043e\u043d double<\/code>: 1e308 * 10<\/code> \u043f\u0435\u0447\u0430\u0442\u0430\u0435\u0442 inf<\/code>, \u043a\u043e\u0434 \u0432\u043e\u0437\u0432\u0440\u0430\u0442\u0430 0, \u0430 scanf<\/code> \u043f\u0440\u0438\u043c\u0435\u0442 \u0438 1e999<\/code> \u043a\u0430\u043a \u0431\u0435\u0441\u043a\u043e\u043d\u0435\u0447\u043d\u043e\u0441\u0442\u044c. \u041e\u0448\u0438\u0431\u043a\u043e\u0439 \u044d\u0442\u043e \u043d\u0435 \u0441\u0447\u0438\u0442\u0430\u0435\u0442\u0441\u044f; \u0435\u0441\u043b\u0438 \u043d\u0443\u0436\u043d\u043e, \u0440\u0435\u0437\u0443\u043b\u044c\u0442\u0430\u0442 \u043f\u0440\u043e\u0432\u0435\u0440\u044f\u044e\u0442 \u043c\u0430\u043a\u0440\u043e\u0441\u043e\u043c isfinite<\/code> \u0438\u0437 <math.h><\/code>, \u043a\u0430\u043a \u0432 \u0440\u0430\u0437\u0431\u043e\u0440\u0449\u0438\u043a\u0435 \u0432\u044b\u0440\u0430\u0436\u0435\u043d\u0438\u0439 \u043d\u0438\u0436\u0435.<\/p>\n
    return 1<\/code> \u043f\u0440\u0438 \u043e\u0448\u0438\u0431\u043a\u0435.<\/strong> \u041a\u043e\u0434 \u0432\u043e\u0437\u0432\u0440\u0430\u0442\u0430 0 \u043e\u0437\u043d\u0430\u0447\u0430\u0435\u0442 \u0443\u0441\u043f\u0435\u0448\u043d\u043e\u0435 \u0437\u0430\u0432\u0435\u0440\u0448\u0435\u043d\u0438\u0435, \u043d\u0435\u043d\u0443\u043b\u0435\u0432\u043e\u0439 — \u043e\u0448\u0438\u0431\u043a\u0443. \u042d\u0442\u043e \u0441\u043e\u0433\u043b\u0430\u0448\u0435\u043d\u0438\u0435 \u0432\u0438\u0434\u044f\u0442 \u0441\u043a\u0440\u0438\u043f\u0442\u044b \u0438 \u043e\u0431\u043e\u043b\u043e\u0447\u043a\u0430 (echo $?<\/code>), \u0437\u043d\u0430\u0447\u0435\u043d\u0438\u044f true\/false \u0442\u0443\u0442 \u043d\u0438 \u043f\u0440\u0438 \u0447\u0435\u043c.<\/p>\n
    \u0422\u0438\u043f\u0438\u0447\u043d\u044b\u0435 \u043e\u0448\u0438\u0431\u043a\u0438: \u043a\u043e\u0434 -> \u0440\u0435\u0437\u0443\u043b\u044c\u0442\u0430\u0442 -> \u0438\u0441\u043f\u0440\u0430\u0432\u043b\u0435\u043d\u0438\u0435<\/h2>\n
    \u0417\u0430\u0431\u044b\u0442\u044b\u0439 break<\/h3>\n
    #include<\/span> <\/span><stdio.h><\/span>\n\nint<\/span> <\/span>main<\/span>(<\/span>void<\/span>) {<\/span>\n    <\/span>double<\/span> <\/span>a<\/span> <\/span>=<\/span> <\/span>6<\/span>, <\/span>b<\/span> <\/span>=<\/span> <\/span>3<\/span>;<\/span>\n    <\/span>char<\/span> <\/span>op<\/span> <\/span>=<\/span> <\/span>'+'<\/span>;<\/span>\n    <\/span>switch<\/span> (<\/span>op<\/span>) {<\/span>\n    <\/span>case<\/span> <\/span>'+'<\/span>:<\/span>\n        <\/span>printf<\/span>(<\/span>\"%g\\n\"<\/span>, <\/span>a<\/span> <\/span>+<\/span> <\/span>b<\/span>);<\/span>\n    <\/span>case<\/span> <\/span>'-'<\/span>:<\/span>\n        <\/span>printf<\/span>(<\/span>\"%g\\n\"<\/span>, <\/span>a<\/span> <\/span>-<\/span> <\/span>b<\/span>);<\/span>\n        <\/span>break<\/span>;<\/span>\n    }<\/span>\n    <\/span>return<\/span> <\/span>0<\/span>;<\/span>\n}<\/span><\/code><\/pre>\n
    \u0420\u0435\u0437\u0443\u043b\u044c\u0442\u0430\u0442: \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u0430 \u043f\u0435\u0447\u0430\u0442\u0430\u0435\u0442 9<\/code>, \u0437\u0430\u0442\u0435\u043c 3<\/code> — \u043f\u043e\u0441\u043b\u0435 \u0441\u043b\u043e\u0436\u0435\u043d\u0438\u044f \u0432\u044b\u043f\u043e\u043b\u043d\u0438\u043b\u043e\u0441\u044c \u0438 \u0432\u044b\u0447\u0438\u0442\u0430\u043d\u0438\u0435. \u041f\u0440\u0435\u0434\u0443\u043f\u0440\u0435\u0436\u0434\u0435\u043d\u0438\u0435 \u0437\u0430\u0432\u0438\u0441\u0438\u0442 \u043e\u0442 \u043a\u043e\u043c\u043f\u0438\u043b\u044f\u0442\u043e\u0440\u0430. GCC \u0432\u043a\u043b\u044e\u0447\u0430\u0435\u0442 \u0435\u0433\u043e \u0432 -Wextra<\/code>:<\/p>\n
    warning: this statement may fall through [-Wimplicit-fallthrough=]\n<\/code><\/pre>\n
    Clang \u0441 -Wall -Wextra<\/code> \u043c\u043e\u043b\u0447\u0438\u0442; \u0443 \u043d\u0435\u0433\u043e \u043f\u0440\u0435\u0434\u0443\u043f\u0440\u0435\u0436\u0434\u0435\u043d\u0438\u0435 \u043f\u043e\u044f\u0432\u043b\u044f\u0435\u0442\u0441\u044f \u0442\u043e\u043b\u044c\u043a\u043e \u0441 \u043e\u0442\u0434\u0435\u043b\u044c\u043d\u044b\u043c \u0444\u043b\u0430\u0433\u043e\u043c -Wimplicit-fallthrough<\/code>:<\/p>\n
    warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]\n<\/code><\/pre>\n
    \u0418\u0441\u043f\u0440\u0430\u0432\u043b\u0435\u043d\u0438\u0435: break<\/code> \u0432 \u043a\u043e\u043d\u0446\u0435 \u043a\u0430\u0436\u0434\u043e\u0439 \u0432\u0435\u0442\u043a\u0438 case<\/code>.<\/p>\n
    \u0426\u0435\u043b\u043e\u0447\u0438\u0441\u043b\u0435\u043d\u043d\u043e\u0435 \u0434\u0435\u043b\u0435\u043d\u0438\u0435<\/h3>\n
    #include<\/span> <\/span><stdio.h><\/span>\n\nint<\/span> <\/span>main<\/span>(<\/span>void<\/span>) {<\/span>\n    <\/span>int<\/span> <\/span>a<\/span> <\/span>=<\/span> <\/span>7<\/span>, <\/span>b<\/span> <\/span>=<\/span> <\/span>2<\/span>;<\/span>\n    <\/span>printf<\/span>(<\/span>\"%d\\n\"<\/span>, <\/span>a<\/span> <\/span>\/<\/span> <\/span>b<\/span>);<\/span>\n    <\/span>printf<\/span>(<\/span>\"%g\\n\"<\/span>, (<\/span>double<\/span>)<\/span>a<\/span> <\/span>\/<\/span> <\/span>b<\/span>);<\/span>\n    <\/span>return<\/span> <\/span>0<\/span>;<\/span>\n}<\/span><\/code><\/pre>\n
    \u0420\u0435\u0437\u0443\u043b\u044c\u0442\u0430\u0442: 3<\/code> \u0438 3.5<\/code>. \u0414\u0435\u043b\u0435\u043d\u0438\u0435 \u0434\u0432\u0443\u0445 int<\/code> \u043e\u0442\u0431\u0440\u0430\u0441\u044b\u0432\u0430\u0435\u0442 \u0434\u0440\u043e\u0431\u043d\u0443\u044e \u0447\u0430\u0441\u0442\u044c. \u0418\u0441\u043f\u0440\u0430\u0432\u043b\u0435\u043d\u0438\u0435: \u0445\u0440\u0430\u043d\u0438\u0442\u044c \u0447\u0438\u0441\u043b\u0430 \u0432 double<\/code> \u0438\u043b\u0438 \u043f\u0440\u0438\u0432\u0435\u0441\u0442\u0438 \u043e\u0434\u0438\u043d \u043e\u043f\u0435\u0440\u0430\u043d\u0434 \u043a double<\/code> \u0434\u043e \u0434\u0435\u043b\u0435\u043d\u0438\u044f.<\/p>\n
    \u0414\u0435\u043b\u0435\u043d\u0438\u0435 \u043d\u0430 \u043d\u043e\u043b\u044c \u0443 int<\/code> — \u043d\u0435\u043e\u043f\u0440\u0435\u0434\u0435\u043b\u0435\u043d\u043d\u043e\u0435 \u043f\u043e\u0432\u0435\u0434\u0435\u043d\u0438\u0435: \u0432 \u0437\u0430\u0432\u0438\u0441\u0438\u043c\u043e\u0441\u0442\u0438 \u043e\u0442 \u043f\u0440\u043e\u0446\u0435\u0441\u0441\u043e\u0440\u0430 \u0438 \u043a\u043e\u043c\u043f\u0438\u043b\u044f\u0442\u043e\u0440\u0430 \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u0430 \u043c\u043e\u0436\u0435\u0442 \u0443\u043f\u0430\u0441\u0442\u044c \u0438\u043b\u0438 \u0432\u0435\u0440\u043d\u0443\u0442\u044c \u043f\u0440\u043e\u0438\u0437\u0432\u043e\u043b\u044c\u043d\u043e\u0435 \u0447\u0438\u0441\u043b\u043e. \u041f\u043e\u044d\u0442\u043e\u043c\u0443 \u0434\u0435\u043b\u0438\u0442\u0435\u043b\u044c \u043f\u0440\u043e\u0432\u0435\u0440\u044f\u044e\u0442 \u0434\u043e \u043e\u043f\u0435\u0440\u0430\u0446\u0438\u0438.<\/p>\n
    \u0411\u0435\u0441\u043a\u043e\u043d\u0435\u0447\u043d\u044b\u0439 \u0446\u0438\u043a\u043b \u043d\u0430 \u0431\u0443\u043a\u0432\u0435<\/h3>\n
    #include<\/span> <\/span><stdio.h><\/span>\n\nint<\/span> <\/span>main<\/span>(<\/span>void<\/span>) {<\/span>\n    <\/span>double<\/span> <\/span>a<\/span>;<\/span>\n    <\/span>while<\/span> (<\/span>scanf<\/span>(<\/span>\"%lf\"<\/span>, <\/span>&<\/span>a<\/span>) <\/span>!=<\/span> <\/span>EOF<\/span>) {<\/span>\n        <\/span>printf<\/span>(<\/span>\"\u043f\u0440\u043e\u0447\u0438\u0442\u0430\u043d\u043e: %g\\n\"<\/span>, <\/span>a<\/span>);<\/span>\n    }<\/span>\n    <\/span>return<\/span> <\/span>0<\/span>;<\/span>\n}<\/span><\/code><\/pre>\n
    \u041d\u0430 \u0432\u0432\u043e\u0434 5 abc<\/code> \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u0430 \u0431\u0435\u0441\u043a\u043e\u043d\u0435\u0447\u043d\u043e \u043f\u0435\u0447\u0430\u0442\u0430\u0435\u0442 \u043f\u0440\u043e\u0447\u0438\u0442\u0430\u043d\u043e: 5<\/code>. scanf<\/code> \u043d\u0435 \u0441\u043c\u043e\u0433 \u043f\u0440\u043e\u0447\u0438\u0442\u0430\u0442\u044c abc<\/code> \u043a\u0430\u043a \u0447\u0438\u0441\u043b\u043e, \u0432\u0435\u0440\u043d\u0443\u043b 0 (\u043d\u0435 EOF<\/code>) \u0438 \u043e\u0441\u0442\u0430\u0432\u0438\u043b \u0431\u0443\u043a\u0432\u044b \u0432\u043e \u0432\u0445\u043e\u0434\u043d\u043e\u043c \u043f\u043e\u0442\u043e\u043a\u0435 — \u043d\u0430 \u0441\u043b\u0435\u0434\u0443\u044e\u0449\u0435\u0439 \u0438\u0442\u0435\u0440\u0430\u0446\u0438\u0438 \u0432\u0441\u0435 \u043f\u043e\u0432\u0442\u043e\u0440\u044f\u0435\u0442\u0441\u044f. \u0418\u0441\u043f\u0440\u0430\u0432\u043b\u0435\u043d\u0438\u0435 — \u0432 \u0441\u043b\u0435\u0434\u0443\u044e\u0449\u0435\u043c \u0440\u0430\u0437\u0434\u0435\u043b\u0435.<\/p>\n
    \u041a\u0430\u043b\u044c\u043a\u0443\u043b\u044f\u0442\u043e\u0440 \u0432 \u0446\u0438\u043a\u043b\u0435 \u0441 \u0443\u0441\u0442\u043e\u0439\u0447\u0438\u0432\u044b\u043c \u0432\u0432\u043e\u0434\u043e\u043c<\/h2>\n
    \u041d\u0430\u0434\u0435\u0436\u043d\u0435\u0435 \u0447\u0438\u0442\u0430\u0442\u044c \u0441\u0442\u0440\u043e\u043a\u0443 \u0446\u0435\u043b\u0438\u043a\u043e\u043c \u0447\u0435\u0440\u0435\u0437 fgets<\/code> \u0438 \u0440\u0430\u0437\u0431\u0438\u0440\u0430\u0442\u044c \u0435\u0435 sscanf<\/code>: \u043d\u0435\u0443\u0434\u0430\u0447\u043d\u0430\u044f \u0441\u0442\u0440\u043e\u043a\u0430 \u043f\u0440\u043e\u043f\u0443\u0441\u043a\u0430\u0435\u0442\u0441\u044f, \u043c\u0443\u0441\u043e\u0440 \u0432 \u043f\u043e\u0442\u043e\u043a\u0435 \u043d\u0435 \u0437\u0430\u0441\u0442\u0440\u0435\u0432\u0430\u0435\u0442.<\/p>\n
    #include<\/span> <\/span><stdio.h><\/span>\n\nint<\/span> <\/span>main<\/span>(<\/span>void<\/span>) {<\/span>\n    <\/span>char<\/span> <\/span>line<\/span>[<\/span>128<\/span>];<\/span>\n    <\/span>double<\/span> <\/span>a<\/span>, <\/span>b<\/span>;<\/span>\n    <\/span>char<\/span> <\/span>op<\/span>;<\/span>\n    <\/span>int<\/span> <\/span>used<\/span>;<\/span>\n\n    <\/span>while<\/span> (<\/span>printf<\/span>(<\/span>\"> \"<\/span>), <\/span>fgets<\/span>(<\/span>line<\/span>, <\/span>sizeof<\/span> <\/span>line<\/span>, <\/span>stdin<\/span>) <\/span>!=<\/span> <\/span>NULL<\/span>) {<\/span>\n        <\/span>if<\/span> (<\/span>line<\/span>[<\/span>0<\/span>] <\/span>==<\/span> <\/span>'q'<\/span>)<\/span>\n            <\/span>break<\/span>;<\/span>\n        <\/span>used<\/span> <\/span>=<\/span> <\/span>0<\/span>;<\/span>\n        <\/span>if<\/span> (<\/span>sscanf<\/span>(<\/span>line<\/span>, <\/span>\"%lf %c %lf %n\"<\/span>, <\/span>&<\/span>a<\/span>, <\/span>&<\/span>op<\/span>, <\/span>&<\/span>b<\/span>, <\/span>&<\/span>used<\/span>) <\/span>!=<\/span> <\/span>3<\/span>\n            <\/span>||<\/span> <\/span>line<\/span>[<\/span>used<\/span>] <\/span>!=<\/span> <\/span>'\\0'<\/span>) {<\/span>\n            <\/span>printf<\/span>(<\/span>\"\u041d\u0435 \u043f\u043e\u043d\u044f\u043b \u0441\u0442\u0440\u043e\u043a\u0443, \u0444\u043e\u0440\u043c\u0430\u0442: 7 \/ 2\\n\"<\/span>);<\/span>\n            <\/span>continue<\/span>;<\/span>\n        }<\/span>\n        <\/span>switch<\/span> (<\/span>op<\/span>) {<\/span>\n        <\/span>case<\/span> <\/span>'+'<\/span>: <\/span>printf<\/span>(<\/span>\"%g\\n\"<\/span>, <\/span>a<\/span> <\/span>+<\/span> <\/span>b<\/span>); <\/span>break<\/span>;<\/span>\n        <\/span>case<\/span> <\/span>'-'<\/span>: <\/span>printf<\/span>(<\/span>\"%g\\n\"<\/span>, <\/span>a<\/span> <\/span>-<\/span> <\/span>b<\/span>); <\/span>break<\/span>;<\/span>\n        <\/span>case<\/span> <\/span>'*'<\/span>: <\/span>printf<\/span>(<\/span>\"%g\\n\"<\/span>, <\/span>a<\/span> <\/span>*<\/span> <\/span>b<\/span>); <\/span>break<\/span>;<\/span>\n        <\/span>case<\/span> <\/span>'\/'<\/span>:<\/span>\n            <\/span>if<\/span> (<\/span>b<\/span> <\/span>==<\/span> <\/span>0<\/span>) <\/span>printf<\/span>(<\/span>\"\u0414\u0435\u043b\u0435\u043d\u0438\u0435 \u043d\u0430 \u043d\u043e\u043b\u044c\\n\"<\/span>);<\/span>\n            <\/span>else<\/span> <\/span>printf<\/span>(<\/span>\"%g\\n\"<\/span>, <\/span>a<\/span> <\/span>\/<\/span> <\/span>b<\/span>);<\/span>\n            <\/span>break<\/span>;<\/span>\n        <\/span>default<\/span>:<\/span> <\/span>printf<\/span>(<\/span>\"\u041d\u0435\u0438\u0437\u0432\u0435\u0441\u0442\u043d\u0430\u044f \u043e\u043f\u0435\u0440\u0430\u0446\u0438\u044f '%c'\\n\"<\/span>, <\/span>op<\/span>);<\/span>\n        }<\/span>\n    }<\/span>\n    <\/span>return<\/span> <\/span>0<\/span>;<\/span>\n}<\/span><\/code><\/pre>\n
    \u041f\u0440\u043e\u0433\u043e\u043d \u043d\u0430 \u0432\u0432\u043e\u0434\u0435 7 \/ 2<\/code>, abc<\/code>, 2 + 3x<\/code>, 5 \/ 0<\/code>, 10 * 1.5<\/code>, q<\/code>:<\/p>\n
    > 3.5\n> \u041d\u0435 \u043f\u043e\u043d\u044f\u043b \u0441\u0442\u0440\u043e\u043a\u0443, \u0444\u043e\u0440\u043c\u0430\u0442: 7 \/ 2\n> \u041d\u0435 \u043f\u043e\u043d\u044f\u043b \u0441\u0442\u0440\u043e\u043a\u0443, \u0444\u043e\u0440\u043c\u0430\u0442: 7 \/ 2\n> \u0414\u0435\u043b\u0435\u043d\u0438\u0435 \u043d\u0430 \u043d\u043e\u043b\u044c\n> 15\n>\n<\/code><\/pre>\n
    %n<\/code> \u0437\u0430\u043f\u0438\u0441\u044b\u0432\u0430\u0435\u0442, \u0441\u043a\u043e\u043b\u044c\u043a\u043e \u0441\u0438\u043c\u0432\u043e\u043b\u043e\u0432 \u0440\u0430\u0437\u043e\u0431\u0440\u0430\u043d\u043e. \u0415\u0441\u043b\u0438 \u043f\u043e\u0441\u043b\u0435 \u0432\u044b\u0440\u0430\u0436\u0435\u043d\u0438\u044f \u043e\u0441\u0442\u0430\u043b\u0441\u044f \u0445\u0432\u043e\u0441\u0442 (2 + 3x<\/code>), line[used]<\/code> \u043d\u0435 \u0440\u0430\u0432\u0435\u043d '\\0'<\/code> \u0438 \u0441\u0442\u0440\u043e\u043a\u0430 \u043e\u0442\u043a\u043b\u043e\u043d\u044f\u0435\u0442\u0441\u044f. \u041f\u0435\u0440\u0432\u0430\u044f \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u0430 \u0442\u0430\u043a\u043e\u0439 \u0445\u0432\u043e\u0441\u0442 \u043c\u043e\u043b\u0447\u0430 \u0438\u0433\u043d\u043e\u0440\u0438\u0440\u0443\u0435\u0442 \u0438 \u0432\u044b\u0434\u0430\u0435\u0442 5. \u0413\u0440\u0430\u043d\u0438\u0446\u0430: \u0441\u0442\u0440\u043e\u043a\u0430 \u0434\u043b\u0438\u043d\u043d\u0435\u0435 127 \u0441\u0438\u043c\u0432\u043e\u043b\u043e\u0432 \u0431\u0443\u0434\u0435\u0442 \u043f\u0440\u043e\u0447\u0438\u0442\u0430\u043d\u0430 \u043f\u043e \u0447\u0430\u0441\u0442\u044f\u043c.<\/p>\n\n\n\n\n\n\n\n
    \u0421\u043f\u043e\u0441\u043e\u0431 \u0432\u0432\u043e\u0434\u0430<\/th>\n\u0427\u0442\u043e \u0434\u0435\u043b\u0430\u0435\u0442 \u0441 \u043c\u0443\u0441\u043e\u0440\u043e\u043c<\/th>\n\u041a\u043e\u0433\u0434\u0430 \u0431\u0440\u0430\u0442\u044c<\/th>\n<\/tr>\n<\/thead>\n
    scanf<\/code><\/td>\n\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u0442 \u0432 \u043f\u043e\u0442\u043e\u043a\u0435, \u0432 \u0446\u0438\u043a\u043b\u0435 \u0432\u043e\u0437\u043c\u043e\u0436\u043d\u043e \u0437\u0430\u0446\u0438\u043a\u043b\u0438\u0432\u0430\u043d\u0438\u0435<\/td>\n\u043e\u0434\u043d\u043e \u0447\u0442\u0435\u043d\u0438\u0435, \u0443\u0447\u0435\u0431\u043d\u044b\u0439 \u043f\u0440\u0438\u043c\u0435\u0440<\/td>\n<\/tr>\n
    fgets<\/code> + sscanf<\/code><\/td>\n\u0441\u0442\u0440\u043e\u043a\u0430 \u043e\u0442\u0431\u0440\u0430\u0441\u044b\u0432\u0430\u0435\u0442\u0441\u044f \u0446\u0435\u043b\u0438\u043a\u043e\u043c<\/td>\n\u0434\u0438\u0430\u043b\u043e\u0433 \u0432 \u0446\u0438\u043a\u043b\u0435<\/td>\n<\/tr>\n
    fgets<\/code> + strtod<\/code><\/td>\n\u0432\u0438\u0434\u043d\u043e, \u0433\u0434\u0435 \u043e\u0441\u0442\u0430\u043d\u043e\u0432\u0438\u043b\u0441\u044f \u0440\u0430\u0437\u0431\u043e\u0440<\/td>\n\u0441\u0432\u043e\u0439 \u0440\u0430\u0437\u0431\u043e\u0440 \u0432\u044b\u0440\u0430\u0436\u0435\u043d\u0438\u0439<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
    \u0420\u0430\u0441\u0448\u0438\u0440\u0435\u043d\u0438\u0435: \u0432\u044b\u0440\u0430\u0436\u0435\u043d\u0438\u044f \u0441\u043e \u0441\u043a\u043e\u0431\u043a\u0430\u043c\u0438<\/h2>\n
    \u0424\u043e\u0440\u043c\u0430\u0442 \u00ab\u0447\u0438\u0441\u043b\u043e, \u0437\u043d\u0430\u043a, \u0447\u0438\u0441\u043b\u043e\u00bb \u043d\u0435 \u0441\u043f\u0440\u0430\u0432\u0438\u0442\u0441\u044f \u0441 2 + 3 * 4<\/code>. \u0414\u043b\u044f \u0432\u044b\u0440\u0430\u0436\u0435\u043d\u0438\u0439 \u0441 \u043f\u0440\u0438\u043e\u0440\u0438\u0442\u0435\u0442\u043e\u043c \u043e\u043f\u0435\u0440\u0430\u0446\u0438\u0439 \u043f\u0438\u0448\u0443\u0442 \u0440\u0435\u043a\u0443\u0440\u0441\u0438\u0432\u043d\u044b\u0439 \u0441\u043f\u0443\u0441\u043a<\/strong>: \u043d\u0430 \u043a\u0430\u0436\u0434\u044b\u0439 \u0443\u0440\u043e\u0432\u0435\u043d\u044c \u043f\u0440\u0438\u043e\u0440\u0438\u0442\u0435\u0442\u0430 — \u0441\u0432\u043e\u044f \u0444\u0443\u043d\u043a\u0446\u0438\u044f. expr<\/code> \u0441\u043a\u043b\u0430\u0434\u044b\u0432\u0430\u0435\u0442 \u0438 \u0432\u044b\u0447\u0438\u0442\u0430\u0435\u0442, term<\/code> \u0443\u043c\u043d\u043e\u0436\u0430\u0435\u0442 \u0438 \u0434\u0435\u043b\u0438\u0442, factor<\/code> \u0447\u0438\u0442\u0430\u0435\u0442 \u0447\u0438\u0441\u043b\u043e, \u0441\u043a\u043e\u0431\u043a\u0438 \u0438\u043b\u0438 \u0443\u043d\u0430\u0440\u043d\u044b\u0439 \u043c\u0438\u043d\u0443\u0441.<\/p>\n
    #include<\/span> <\/span><stdio.h><\/span>\n#include<\/span> <\/span><stdlib.h><\/span>\n#include<\/span> <\/span><ctype.h><\/span>\n#include<\/span> <\/span><math.h><\/span>\n\nstatic<\/span> <\/span>const<\/span> <\/span>char<\/span> <\/span>*<\/span>p<\/span>;   <\/span>\/* \u0442\u0435\u043a\u0443\u0449\u0430\u044f \u043f\u043e\u0437\u0438\u0446\u0438\u044f \u0432 \u0441\u0442\u0440\u043e\u043a\u0435 *\/<\/span>\nstatic<\/span> <\/span>int<\/span> <\/span>error<\/span>;       <\/span>\/* 1, \u0435\u0441\u043b\u0438 \u0440\u0430\u0437\u0431\u043e\u0440 \u043d\u0435 \u0443\u0434\u0430\u043b\u0441\u044f *\/<\/span>\n\nstatic<\/span> <\/span>double<\/span> <\/span>expr<\/span>(<\/span>void<\/span>);<\/span>\n\nstatic<\/span> <\/span>void<\/span> <\/span>skip_spaces<\/span>(<\/span>void<\/span>) {<\/span>\n    <\/span>while<\/span> (<\/span>isspace<\/span>((<\/span>unsigned<\/span> <\/span>char<\/span>)<\/span>*<\/span>p<\/span>)) <\/span>p<\/span>++<\/span>;<\/span>\n}<\/span>\n\n\/* \u0447\u0438\u0441\u043b\u043e | ( \u0432\u044b\u0440\u0430\u0436\u0435\u043d\u0438\u0435 ) | -\u043c\u043d\u043e\u0436\u0438\u0442\u0435\u043b\u044c *\/<\/span>\nstatic<\/span> <\/span>double<\/span> <\/span>factor<\/span>(<\/span>void<\/span>) {<\/span>\n    <\/span>skip_spaces<\/span>();<\/span>\n    <\/span>if<\/span> (<\/span>*<\/span>p<\/span> <\/span>==<\/span> <\/span>'('<\/span>) {<\/span>\n        <\/span>p<\/span>++<\/span>;<\/span>\n        <\/span>double<\/span> <\/span>v<\/span> <\/span>=<\/span> <\/span>expr<\/span>();<\/span>\n        <\/span>skip_spaces<\/span>();<\/span>\n        <\/span>if<\/span> (<\/span>*<\/span>p<\/span> <\/span>==<\/span> <\/span>')'<\/span>) <\/span>p<\/span>++<\/span>; <\/span>else<\/span> <\/span>error<\/span> <\/span>=<\/span> <\/span>1<\/span>;<\/span>\n        <\/span>return<\/span> <\/span>v<\/span>;<\/span>\n    }<\/span>\n    <\/span>if<\/span> (<\/span>*<\/span>p<\/span> <\/span>==<\/span> <\/span>'-'<\/span>) { <\/span>p<\/span>++<\/span>; <\/span>return<\/span> <\/span>-<\/span>factor<\/span>(); }<\/span>\n    <\/span>char<\/span> <\/span>*<\/span>end<\/span>;<\/span>\n    <\/span>double<\/span> <\/span>v<\/span> <\/span>=<\/span> <\/span>strtod<\/span>(<\/span>p<\/span>, <\/span>&<\/span>end<\/span>);<\/span>\n    <\/span>if<\/span> (<\/span>end<\/span> <\/span>==<\/span> <\/span>p<\/span>) <\/span>error<\/span> <\/span>=<\/span> <\/span>1<\/span>;<\/span>\n    <\/span>p<\/span> <\/span>=<\/span> <\/span>end<\/span>;<\/span>\n    <\/span>return<\/span> <\/span>v<\/span>;<\/span>\n}<\/span>\n\n\/* \u043c\u043d\u043e\u0436\u0438\u0442\u0435\u043b\u044c { (* | \/) \u043c\u043d\u043e\u0436\u0438\u0442\u0435\u043b\u044c } *\/<\/span>\nstatic<\/span> <\/span>double<\/span> <\/span>term<\/span>(<\/span>void<\/span>) {<\/span>\n    <\/span>double<\/span> <\/span>v<\/span> <\/span>=<\/span> <\/span>factor<\/span>();<\/span>\n    <\/span>for<\/span> (;;) {<\/span>\n        <\/span>skip_spaces<\/span>();<\/span>\n        <\/span>if<\/span> (<\/span>*<\/span>p<\/span> <\/span>==<\/span> <\/span>'*'<\/span>) { <\/span>p<\/span>++<\/span>; <\/span>v<\/span> <\/span>*=<\/span> <\/span>factor<\/span>(); }<\/span>\n        <\/span>else<\/span> <\/span>if<\/span> (<\/span>*<\/span>p<\/span> <\/span>==<\/span> <\/span>'\/'<\/span>) {<\/span>\n            <\/span>p<\/span>++<\/span>;<\/span>\n            <\/span>double<\/span> <\/span>d<\/span> <\/span>=<\/span> <\/span>factor<\/span>();<\/span>\n            <\/span>if<\/span> (<\/span>d<\/span> <\/span>==<\/span> <\/span>0<\/span>) <\/span>error<\/span> <\/span>=<\/span> <\/span>1<\/span>; <\/span>else<\/span> <\/span>v<\/span> <\/span>\/=<\/span> <\/span>d<\/span>;<\/span>\n        }<\/span>\n        <\/span>else<\/span> <\/span>return<\/span> <\/span>v<\/span>;<\/span>\n    }<\/span>\n}<\/span>\n\n\/* \u0441\u043b\u0430\u0433\u0430\u0435\u043c\u043e\u0435 { (+ | -) \u0441\u043b\u0430\u0433\u0430\u0435\u043c\u043e\u0435 } *\/<\/span>\nstatic<\/span> <\/span>double<\/span> <\/span>expr<\/span>(<\/span>void<\/span>) {<\/span>\n    <\/span>double<\/span> <\/span>v<\/span> <\/span>=<\/span> <\/span>term<\/span>();<\/span>\n    <\/span>for<\/span> (;;) {<\/span>\n        <\/span>skip_spaces<\/span>();<\/span>\n        <\/span>if<\/span> (<\/span>*<\/span>p<\/span> <\/span>==<\/span> <\/span>'+'<\/span>) { <\/span>p<\/span>++<\/span>; <\/span>v<\/span> <\/span>+=<\/span> <\/span>term<\/span>(); }<\/span>\n        <\/span>else<\/span> <\/span>if<\/span> (<\/span>*<\/span>p<\/span> <\/span>==<\/span> <\/span>'-'<\/span>) { <\/span>p<\/span>++<\/span>; <\/span>v<\/span> <\/span>-=<\/span> <\/span>term<\/span>(); }<\/span>\n        <\/span>else<\/span> <\/span>return<\/span> <\/span>v<\/span>;<\/span>\n    }<\/span>\n}<\/span>\n\nint<\/span> <\/span>main<\/span>(<\/span>void<\/span>) {<\/span>\n    <\/span>const<\/span> <\/span>char<\/span> <\/span>*<\/span>tests<\/span>[] <\/span>=<\/span> { <\/span>\"2 + 3 * 4\"<\/span>, <\/span>\"(2 + 3) * 4\"<\/span>, <\/span>\"10 \/ 4 - 1\"<\/span>,<\/span>\n                            <\/span>\"-(1 + 2) * 2\"<\/span>, <\/span>\"1 \/ 0\"<\/span>, <\/span>\"2 + * 3\"<\/span>, <\/span>\"(1 + 2\"<\/span>,<\/span>\n                            <\/span>\"1e308 * 10\"<\/span> };<\/span>\n    <\/span>for<\/span> (<\/span>size_t<\/span> <\/span>i<\/span> <\/span>=<\/span> <\/span>0<\/span>; <\/span>i<\/span> <\/span><<\/span> <\/span>sizeof<\/span> <\/span>tests<\/span> <\/span>\/<\/span> <\/span>sizeof<\/span> <\/span>tests<\/span>[<\/span>0<\/span>]; <\/span>i<\/span>++<\/span>) {<\/span>\n        <\/span>p<\/span> <\/span>=<\/span> <\/span>tests<\/span>[<\/span>i<\/span>];<\/span>\n        <\/span>error<\/span> <\/span>=<\/span> <\/span>0<\/span>;<\/span>\n        <\/span>double<\/span> <\/span>v<\/span> <\/span>=<\/span> <\/span>expr<\/span>();<\/span>\n        <\/span>skip_spaces<\/span>();<\/span>\n        <\/span>if<\/span> (<\/span>error<\/span> <\/span>||<\/span> <\/span>*<\/span>p<\/span> <\/span>!=<\/span> <\/span>'\\0'<\/span> <\/span>||<\/span> <\/span>!<\/span>isfinite<\/span>(<\/span>v<\/span>))<\/span>\n            <\/span>printf<\/span>(<\/span>\"%-14s -> \u043e\u0448\u0438\u0431\u043a\u0430\\n\"<\/span>, <\/span>tests<\/span>[<\/span>i<\/span>]);<\/span>\n        <\/span>else<\/span>\n            <\/span>printf<\/span>(<\/span>\"%-14s -> %g\\n\"<\/span>, <\/span>tests<\/span>[<\/span>i<\/span>], <\/span>v<\/span>);<\/span>\n    }<\/span>\n    <\/span>return<\/span> <\/span>0<\/span>;<\/span>\n}<\/span><\/code><\/pre>\n
    \u0412\u044b\u0432\u043e\u0434:<\/p>\n
    2 + 3 * 4      -> 14\n(2 + 3) * 4    -> 20\n10 \/ 4 - 1     -> 1.5\n-(1 + 2) * 2   -> -6\n1 \/ 0          -> \u043e\u0448\u0438\u0431\u043a\u0430\n2 + * 3        -> \u043e\u0448\u0438\u0431\u043a\u0430\n(1 + 2         -> \u043e\u0448\u0438\u0431\u043a\u0430\n1e308 * 10     -> \u043e\u0448\u0438\u0431\u043a\u0430\n<\/code><\/pre>\n
    \u0423\u043c\u043d\u043e\u0436\u0435\u043d\u0438\u0435 \u0432\u044b\u043f\u043e\u043b\u043d\u0438\u043b\u043e\u0441\u044c \u0440\u0430\u043d\u044c\u0448\u0435 \u0441\u043b\u043e\u0436\u0435\u043d\u0438\u044f, \u043f\u043e\u0442\u043e\u043c\u0443 \u0447\u0442\u043e term<\/code> \u0432\u044b\u0437\u044b\u0432\u0430\u0435\u0442\u0441\u044f \u0438\u0437\u043d\u0443\u0442\u0440\u0438 expr<\/code>: \u043f\u0440\u0438\u043e\u0440\u0438\u0442\u0435\u0442 \u0437\u0430\u0434\u0430\u043d \u0432\u043b\u043e\u0436\u0435\u043d\u043d\u043e\u0441\u0442\u044c\u044e \u0444\u0443\u043d\u043a\u0446\u0438\u0439. \u041f\u0440\u043e\u0432\u0435\u0440\u043a\u0430 isfinite<\/code> \u0432 main<\/code> \u043e\u0442\u0441\u0435\u043a\u0430\u0435\u0442 \u043f\u0435\u0440\u0435\u043f\u043e\u043b\u043d\u0435\u043d\u0438\u0435 (1e308 * 10<\/code> \u0434\u0430\u0435\u0442 \u0431\u0435\u0441\u043a\u043e\u043d\u0435\u0447\u043d\u043e\u0441\u0442\u044c, \u0430 \u043d\u0435 \u043e\u0448\u0438\u0431\u043a\u0443 \u043e\u043f\u0435\u0440\u0430\u0446\u0438\u0438) \u0438 \u0437\u0430\u043e\u0434\u043d\u043e \u0432\u0432\u0435\u0434\u0435\u043d\u043d\u044b\u0435 inf<\/code> \u0438 nan<\/code>: strtod<\/code> \u043f\u0440\u0438\u043d\u0438\u043c\u0430\u0435\u0442 \u0438\u0445 \u043a\u0430\u043a \u0447\u0438\u0441\u043b\u0430, \u0442\u0430\u043a \u0436\u0435 \u043a\u0430\u043a 1e3<\/code> \u0438 \u0448\u0435\u0441\u0442\u043d\u0430\u0434\u0446\u0430\u0442\u0435\u0440\u0438\u0447\u043d\u043e\u0435 0x10<\/code>. \u042d\u0442\u043e \u0443\u0447\u0435\u0431\u043d\u0430\u044f \u0432\u0435\u0440\u0441\u0438\u044f: \u0433\u043b\u043e\u0431\u0430\u043b\u044c\u043d\u043e\u0435 \u0441\u043e\u0441\u0442\u043e\u044f\u043d\u0438\u0435, \u0431\u0435\u0437 \u0441\u0442\u0435\u043f\u0435\u043d\u0438, \u0430 \u0441\u043b\u0438\u0448\u043a\u043e\u043c \u0433\u043b\u0443\u0431\u043e\u043a\u0430\u044f \u0432\u043b\u043e\u0436\u0435\u043d\u043d\u043e\u0441\u0442\u044c \u0441\u043a\u043e\u0431\u043e\u043a \u0438\u043b\u0438 \u0434\u043b\u0438\u043d\u043d\u0430\u044f \u0446\u0435\u043f\u043e\u0447\u043a\u0430 \u0443\u043d\u0430\u0440\u043d\u044b\u0445 \u043c\u0438\u043d\u0443\u0441\u043e\u0432 \u043f\u0435\u0440\u0435\u043f\u043e\u043b\u043d\u0438\u0442 \u0441\u0442\u0435\u043a (\u0441 -fsanitize=address<\/code> \u043d\u0430 200 000 \u043c\u0438\u043d\u0443\u0441\u0430\u0445 — stack-overflow<\/code>). \u0414\u0435\u0441\u044f\u0442\u0438\u0447\u043d\u044b\u0439 \u0440\u0430\u0437\u0434\u0435\u043b\u0438\u0442\u0435\u043b\u044c \u0432 strtod<\/code> \u0437\u0430\u0432\u0438\u0441\u0438\u0442 \u043e\u0442 \u043b\u043e\u043a\u0430\u043b\u0438, \u0435\u0441\u043b\u0438 \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u0430 \u0432\u044b\u0437\u044b\u0432\u0430\u0435\u0442 setlocale<\/code>.<\/p>\n
    \u0421\u0442\u0435\u043f\u0435\u043d\u044c \u0434\u043e\u0431\u0430\u0432\u043b\u044f\u0435\u0442\u0441\u044f \u0444\u0443\u043d\u043a\u0446\u0438\u0435\u0439 pow<\/code> \u0438\u0437 <math.h><\/code>. \u041d\u0430 Linux \u0441 GCC \u0438 glibc \u0434\u043b\u044f \u043d\u0435\u0435 \u043d\u0443\u0436\u0435\u043d \u0444\u043b\u0430\u0433 -lm<\/code> \u043f\u0440\u0438 \u0441\u0431\u043e\u0440\u043a\u0435 (\u0431\u0435\u0437 \u043d\u0435\u0433\u043e \u043d\u0430 Ubuntu 24.04 — undefined reference to 'pow'<\/code>; \u0438\u0441\u043a\u043b\u044e\u0447\u0435\u043d\u0438\u0435 — \u0432\u044b\u0437\u043e\u0432 \u0441 \u043a\u043e\u043d\u0441\u0442\u0430\u043d\u0442\u0430\u043c\u0438, \u043a\u043e\u0442\u043e\u0440\u044b\u0439 \u043a\u043e\u043c\u043f\u0438\u043b\u044f\u0442\u043e\u0440 \u0432\u044b\u0447\u0438\u0441\u043b\u044f\u0435\u0442 \u0441\u0430\u043c), \u043d\u0430 macOS \u043c\u0430\u0442\u0435\u043c\u0430\u0442\u0438\u0447\u0435\u0441\u043a\u0430\u044f \u0431\u0438\u0431\u043b\u0438\u043e\u0442\u0435\u043a\u0430 \u043f\u043e\u0434\u043a\u043b\u044e\u0447\u0435\u043d\u0430 \u043f\u043e \u0443\u043c\u043e\u043b\u0447\u0430\u043d\u0438\u044e. \u041c\u0430\u043a\u0440\u043e\u0441\u0443 isfinite<\/code> \u0444\u043b\u0430\u0433 \u043d\u0435 \u043d\u0443\u0436\u0435\u043d.<\/p>\n
    \u0415\u0441\u043b\u0438 \u043d\u0435 \u043f\u043e\u043b\u0443\u0447\u0438\u043b\u043e\u0441\u044c<\/h2>\n