Compilare: main.c: In function 'main': main.c:47:12: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses] if (ult[v[i]]==i) ^ main.c:11:5: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen ("decrease.in","r", stdin); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:12:5: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen ("decrease.out","w", stdout); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:14:5: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^~~~~~~~~~~~~~ main.c:17:9: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] scanf("%u\n",&v[i]); ^~~~~~~~~~~~~~~~~~~