Compilare: main.c: In function 'main': main.c:20:5: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("pietre2.in","r",stdin),freopen("pietre2.out","w",stdout),scanf("%d",&n); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:20:37: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("pietre2.in","r",stdin),freopen("pietre2.out","w",stdout),scanf("%d",&n); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:20:71: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] freopen("pietre2.in","r",stdin),freopen("pietre2.out","w",stdout),scanf("%d",&n); ^~~~~~~~~~~~~~ main.c:23:13: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&a[i][j]); ^~~~~~~~~~~~~~~~~~~~