Compilare: main.cpp: In function 'bool in(std::__cxx11::string, std::__cxx11::string)': main.cpp:17:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (x == a.size()) ~~^~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:24:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("interesant.in", "r", stdin); ^ main.cpp:25:41: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("interesant.out", "w", stdout); ^ main.cpp:28:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &c, &n); ^