Compilare: user.c:14:11: warning: return type of ‘main’ is not ‘int’ [-Wmain] long long main() ^ user.c: In function ‘main’: user.c:44:3: warning: implicit declaration of function ‘qsort’ [-Wimplicit-function-declaration] qsort(negative, nneg, sizeof(long long), cmp_less); ^ user.c:28:13: warning: unused variable ‘v4’ [-Wunused-variable] long long v4 = 0; ^ user.c:18:9: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("produs4.in", "r", stdin); ^ user.c:19:9: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("produs4.out", "w", stdout); ^ user.c:21:7: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld", &T); ^ user.c:32:8: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld", &N); ^ user.c:35:9: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld", &x); ^