Compilare: main.c: In function 'main': main.c:30:2: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("sortaret.in","r",stdin),freopen("sortaret.out","w",stdout),scanf("%d%d",&n,&m); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:30:35: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("sortaret.in","r",stdin),freopen("sortaret.out","w",stdout),scanf("%d%d",&n,&m); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:30:70: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] freopen("sortaret.in","r",stdin),freopen("sortaret.out","w",stdout),scanf("%d%d",&n,&m); ^~~~~~~~~~~~~~~~~~~ main.c:32:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&a,&b),nr[a]++; ^~~~~~~~~~~~~~~~~~~ main.c:36:2: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("sortaret.in","r",stdin),scanf("%d%d",&n,&m); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:36:35: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] freopen("sortaret.in","r",stdin),scanf("%d%d",&n,&m); ^~~~~~~~~~~~~~~~~~~ main.c:38:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&a,&b); ^~~~~~~~~~~~~~~~~~~