Compilare: user.cpp: In function ‘void DFS(int, int)’: user.cpp:15:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<G[st].size();i++) ^ user.cpp:16:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<G[dr].size();j++) ^ user.cpp: In function ‘void arb()’: user.cpp:25:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<G[i].size();j++) ^ user.cpp:26:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(q=j+1;q<G[i].size();q++) ^ user.cpp: In function ‘int main()’: user.cpp:47:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("arbpal.in","r",stdin); ^ user.cpp:48:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("arbpal.out","w",stdout); ^ user.cpp:49:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:51:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&a,&b); ^ user.cpp:56:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s",&ch[i]); ^