OJ-Problems-Source/HDOJ/4714_autoAC.cpp

#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<string>
#include<queue>
#include<algorithm>
#include<map>
#include<iomanip>
#define INF 99999999
using namespace std;
#pragma comment(linker,"/STACK:102400000,102400000")
const int MAX=1000000+10;
int head[MAX],size,sum=0; 
struct Edge{
    int v,next;
    Edge(){}
    Edge(int V,int NEXT):v(V),next(NEXT){}
}edge[MAX*2];
void Init(int num){
    memset(head,-1,sizeof(int)*(num+1));
    size=sum=0;
}
void InsertEdge(int u,int v){
    edge[size]=Edge(v,head[u]);
    head[u]=size++;
}
int dfs(int u,int father){
    int num=0,v;
    for(int i=head[u];i != -1;i=edge[i].next){
        int v=edge[i].v;
        if(v == father)continue;
        num+=dfs(v,u);
    }
    if(num>=2){
        if(u == 1)sum+=num-2;
        else sum+=num-1;
        return 0;
    }else return 1;
}
int main(){
    int t,n,u,v;
    scanf("%d",&t);
    while(t--){
        scanf("%d",&n);
        Init(n);
        for(int i=1;i<n;++i){
            scanf("%d%d",&u,&v);
            InsertEdge(u,v);
            InsertEdge(v,u);
        }
        dfs(1,0);
        printf("%d\n",sum*2+1);
    }
    return 0;
}