Compilare: main.c: In function 'main': main.c:10:11: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses] if(o) ^ main.c:5:5: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("permutari.in","r",stdin),freopen("permutari.out","w",stdout),scanf("%d",&n); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:5:39: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("permutari.in","r",stdin),freopen("permutari.out","w",stdout),scanf("%d",&n); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:5:75: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] freopen("permutari.in","r",stdin),freopen("permutari.out","w",stdout),scanf("%d",&n); ^~~~~~~~~~~~~~