Compilare: user.cpp: In function ‘void baga(int)’: user.cpp:19:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0; j < a[x].size(); j++) ^ user.cpp: In function ‘int main()’: user.cpp:32:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("psychtraining.in","r",stdin); ^ user.cpp:33:44: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("psychtraining.out","w",stdout); ^ user.cpp:34:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&n,&m); ^ user.cpp:37:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&x,&y); ^