Compilare: user.cpp: In function ‘int main()’: user.cpp:28:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("flux.in", "r", stdin); ^ user.cpp:29:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("flux.out", "w", stdout); ^ user.cpp:31:37: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d %d", &N, &M), eps = 1e-11; ^ user.cpp:35:130: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d %d %d", &a[i], &b[i], &c[i]), cnt[a[i]] ++, cnt[b[i]] ++, ap[a[i]][b[i]] ++, ap[b[i]][a[i]] ++, unite (a[i], b[i]); ^