Compilare: user.cpp: In function ‘int main()’: user.cpp:4:32: warning: variable ‘col2’ set but not used [-Wunused-but-set-variable] int n,m,i,j,min1,min2,col1,col2,min3,min4,col3,col4,val; ^ user.cpp:5:36: 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:6:38: 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); ^ user.cpp:7:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:10:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&a[i][j]); ^ user.cpp:4:47: warning: ‘col3’ may be used uninitialized in this function [-Wmaybe-uninitialized] int n,m,i,j,min1,min2,col1,col2,min3,min4,col3,col4,val; ^