Compilare: user.cpp: In function ‘int main()’: user.cpp:75:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(k = 0; k < G[j].size(); k++) ^ user.cpp:59:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("inter.in", "r", stdin); ^ user.cpp:60:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("inter.out", "w", stdout); ^ user.cpp:64:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d\n", &N, &M); ^ user.cpp:66:53: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &a, &b), G[a].pb(b), deg[b]++; ^