ccf 送货

#include<iostream>#include<cstring>#include<cstdio>#include<queue>#include<vector>using namespace std;vector<int> a[1001];int main(){int n,m,x,y,count=0;scanf("%d%d",&n,&m);memset(a,0,sizeof(a));for(int i=0;i<m;i++){scanf("%d%d",&x,&y);a[x][y]=a[y][x]=1;}int path[10001],k=1;queue<int> q;q.push(1);path[0]=1;while(!q.empty()){int tmp=q.front();q.pop();for(int i=1;i<=n;i++){if(a[tmp][i]){a[tmp][i]=a[i][tmp]=0;count++;path[k++]=i;q.push(i);break; }}}if(count==m){cout<<path[0];for(int i=1;i<k;i++){cout<<' '<<path[i];}cout<<endl; }else{cout<<-1<<endl;}return 0;}