Compilare: user.c: In function ‘main’: user.c:10:15: warning: unused variable ‘y’ [-Wunused-variable] int i,j,x,y; ^ user.c:10:13: warning: unused variable ‘x’ [-Wunused-variable] int i,j,x,y; ^ user.c:8:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("flip.in","r",stdin); ^ user.c:11:10: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.c:13:14: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&t[i][j]); ^ user.c:42:15: warning: ‘vj’ may be used uninitialized in this function [-Wmaybe-uninitialized] if(i!=vj){ ^ user.c:22:25: warning: ‘vi’ may be used uninitialized in this function [-Wmaybe-uninitialized] long long minv,minf,vi,vj; ^