# include<stdio.h> # include<string.h> # include<vector> using namespace std; vector<int >a[100005]; //用动态数组 int h[100005],v[100005]; int n,m; void dfs(int k) { v[k]=1; for(int i=0;i<a[k].size();i++) { if(!v[a[k][i]]) { h[a[k][i]]=k; dfs(a[k][i]); } } } int main(){ int t; scanf("%d",&t); while(t--) { scanf("%d%d",&n,&m); memset(v,0,sizeof(v)); memset(a,0,sizeof(a)); h[m]=-1; int c1,c2; for(int i=1;i<n;i++) { scanf("%d%d",&c1,&c2); a[c1].push_back(c2); a[c2].push_back(c1); } dfs(m); for(int i=1;i<=n;i++) printf("%d ",h[i]); printf("\n"); } return 0; }