UVA 1267 Network(dfs)

//
//  main.cpp
//  Richard
//
//  Created by 邵金杰 on 16/9/30.
//  Mail:1016427040@qq.com or jasonshaosjj@gmail.com
//  Copyright © 2016年 邵金杰. All rights reserved.
//

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<vector>
using namespace std;
const int maxn=1000+10;
vector<vector<int> > G(maxn),node(maxn);
int n,s,k;
int fa[maxn];
int covered[maxn];
void dfs1(int u,int f,int d)
{
fa[u]=f;
int nc=(int)G[u].size();
if(nc==1&&d>k) node[d].push_back(u);
for(int i=0;i<G[u].size();i++){
int v=G[u][i];
if(v!=f) dfs1(v,u,d+1);
}
}
void dfs2(int u,int f,int d)
{
covered[u]=1;
for(int i=0;i<G[u].size();i++){
int v=G[u][i];
if(v!=f&&d<k) dfs2(v,u,d+1);
}
}
int solve()
{
int ans=0;
memset(covered,0,sizeof(covered));
for(int d=n-1;d>k;d--)
{
for(int i=0;i<node[d].size();i++){
int p=node[d][i];
if(covered[p]) continue;
int v=p;
for(int j=0;j<k;j++) v=fa[v];
dfs2(v,-1,0);
ans++;
}
}
return ans;
}
int main()
{
int t;
scanf("%d",&t);
while(t--)
{
int u,v;
scanf("%d%d%d",&n,&s,&k);
for(int i=0;i<=n;i++) G[i].clear(),node[i].clear();
for(int i=0;i<n-1;i++)
{
scanf("%d%d",&u,&v);
G[u].push_back(v);
G[v].push_back(u);
}
dfs1(s,-1,0);
printf("%d\n",solve());
}
return 0;
}

//2 14
//12 2
//1 2
//2 3
//3 4
//4 5
//5 6
//7 5
//8 5
//4 9
//10 3
//2 12
//12 14
//13 14
//14 11