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:26:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<G[i].size();j++) ^ user.cpp:27:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(q=0;q<G[i].size();q++) ^ user.cpp: In function ‘void arb2()’: user.cpp:47:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(it-G[i].begin() < G[i].size()){ ^ user.cpp:50:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(q = 0; q < G[i].size();q++) ^ user.cpp:51:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(k=0;k<G[j].size();k++) ^ user.cpp:38:13: warning: unused variable ‘t’ [-Wunused-variable] int i,j,t[nmax],q,k; ^ user.cpp: In function ‘int main()’: user.cpp:62:35: 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:63:37: 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:64:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:66:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&a,&b); ^ user.cpp:71:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s",&ch[i]); ^