Compilare: main.cpp: In function 'int main()': main.cpp:82:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < v.size() ; i++) ~~^~~~~~~~~~ main.cpp:32:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("date.in","r",stdin); ^ main.cpp:33:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("date.out","w",stdout); ^ main.cpp:34:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&m,&n); ^ main.cpp:37:33: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&a[i][j]); ^