Compilare: main.cpp: In function 'int main()': main.cpp:46:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0 ; i < ans.size() ; i ++) ~~^~~~~~~~~~~~ main.cpp:12:41: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("strmatch.in" , "r" , stdin); ^ main.cpp:13:43: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("strmatch.out" , "w" , stdout); ^