Compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:17:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0; i<v[nod].size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:55:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0; j<sol[i].size(); j++) ^ user.cpp:41:36: 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:42:38: 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:43:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:46:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^