Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:22:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<G[node].size(); ++i) ^ user.cpp: In function ‘int main()’: user.cpp:32:18: warning: variable ‘edges’ set but not used [-Wunused-but-set-variable] int x, y, i, edges, e, son, j, node, ans = 0; ^ user.cpp:29:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("johnie.in", "r", stdin); ^ user.cpp:30:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("johnie.out", "w", stdout); ^ user.cpp:34:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:38:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^