Compilare: user.c: In function ‘main’: user.c:19:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("qvect.in","r",stdin); ^ user.c:20:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("qvect.out","w",stdout); ^ user.c:22:10: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%hd %hd",&N,&Q); ^ user.c:25:14: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&A[i][0]); ^ user.c:27:18: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&A[i][j]); ^ user.c:33:14: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%hd %hd %hd",&t,&i,&j); ^ user.c: In function ‘t2’: user.c:81:21: warning: ‘val’ may be used uninitialized in this function [-Wmaybe-uninitialized] C[i][j] = val; ^