Compilare: user.c: In function ‘main’: user.c:11:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("cartele.in","r",stdin),freopen("cartele.out","w",stdout),scanf("%d%d",&n,&c); ^ user.c:11:44: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("cartele.in","r",stdin),freopen("cartele.out","w",stdout),scanf("%d%d",&n,&c); ^ user.c:11:76: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] freopen("cartele.in","r",stdin),freopen("cartele.out","w",stdout),scanf("%d%d",&n,&c); ^ user.c:14:14: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&a[i][j]); ^ user.c:18:18: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&b[i][j]); ^