#include <iostream>#include <queue>using namespace std;const int N=20;int g[N][N],bz[N]={0},n,flag=0;void bfs(int x){ int t,i;queue <int> q;q.push(x); bz[x]=1;while (!q.empty()){ t=q.front(); q.pop(); if (flag==0)        {  cout<<t; flag=1;}         else cout<<" "<<t;     for (i=0; i<n; i++)  if (g[i][t]==1 && bz[i]==0)       { q.push(i); bz[i]=1;}} }int main(int argc, char *argv[]){int i,t,x,y;cin>>n>>t;for (i=1; i<=t; i++) {  cin>>x>>y; g[x][y]=g[y][x]=1; }bfs(0);cout<<endl;return 0;}

#include <iostream>#include<queue>using namespace std;const int N=20;int g[N][N],bz[N]={0};int n;void bfs(int x){    int t,i;    int c=0;    queue<int>q;    q.push(x);  bz[x]=1;    while(!q.empty())    {  t=q.front();  q.pop();c++;         if(c==1)cout<<t;        else cout<<" "<<t;        for(i=0;i<n;i++)          if(g[i][t]==1 && bz[i]==0){  q.push(i); bz[i]=1;}    }}int main(int argc, char *argv[]){ int i,t,x,y; cin>>n>>t; for(i=1;i<=t;i++) {     cin>>x>>y;     g[x][y]=g[y][x]=1; }     bfs(0); cout<<endl;    return 0;}