Compilare: user.cpp: In function ‘int main()’: user.cpp:83:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[N].size();i++){ ^ user.cpp:68:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("critice.in","r",stdin); ^ user.cpp:69:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("critice.out","w",stdout); ^ user.cpp:70:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&N,&M); ^ user.cpp:74:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&x,&y,&c); ^