Compilare: main.cpp: In function 'int main()': main.cpp:25:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < s.size(); ++i) { ~~^~~~~~~~~~ main.cpp:29:17: warning: operation on 'p' may be undefined [-Wsequence-point] sum[++p] = (s[i - 1] == '/') ? - sum[p - 1] : sum[p - 1]; ^~~ main.cpp:21:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("expresie3.in", "r", stdin); ^ main.cpp:22:42: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("expresie3.out", "w", stdout); ^