Compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:22:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1; i < G[nod].size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:49:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("biconex.in", "r", stdin); ^ user.cpp:50:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("biconex.out", "w", stdout); ^ user.cpp:51:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp:58:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^