Compilare: user.cpp: In function ‘int main()’: user.cpp:9:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<m;i++) ^ user.cpp:10:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<n;j++) ^ user.cpp:7:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("lacusta.in","r",stdin); ^ user.cpp:8:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&m,&n); ^ user.cpp:11:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&a[i][j]); ^ user.cpp:50:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("lacusta.out","w",stdout); ^