样例过了
#include<bits/stdc++.h>
using namespace std;
int n,m;
map<int,vector<int> >mp;
int book[100005];
void dfs(int hhh){
if(book[hhh]==0){
book[hhh]=1;
cout<<hhh<<" ";
for(int i=0;i<mp[hhh].size();i++){
dfs(mp[hhh][i]);
}
}else{
return;
}
}
int main(){
cin>>n>>m;
for(int i=1;i<=m;i++){
int x,y;
cin>>x>>y;
mp[x].push_back(y);
}
dfs(1);
cout<<endl;
memset(book,0,sizeof(book));
queue<int>q;
q.push(1);
book[1]=1;
while(!q.empty()){
int tmp=q.front();
q.pop();
cout<<tmp<<" ";
for(int i=0;i<mp[tmp].size();i++){
int ntmp=mp[tmp][i];
if(book[ntmp]==0){
q.push(ntmp);
book[ntmp]=1;
}
}
}
return 0;
}