Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:36:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<G[u].size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:79:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=1; j<rasp[i].size(); j++) ^ user.cpp:58:38: 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:59:39: 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:61:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:65:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &u,&v); ^