Compilare: main.c: In function 'main': main.c:4:2: 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:4:35: 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:4:70: 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:6:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&a,&b),w[a]++; ^~~~~~~~~~~~~~~~~~~ main.c:10:2: 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:10:35: 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:12:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&a,&b); ^~~~~~~~~~~~~~~~~~~