[hdu4714 Tree2cycle]树形DP

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#pragma comment(linker, "/STACK:10240000")
#include <map>
#include <set>
#include <cmath>
#include <ctime>
#include <deque>
#include <queue>
#include <stack>
#include <vector>
#include <cstdio>
#include <string>
#include <cstdlib>
#include <cstring>
#include <iostream>
#include <algorithm>

using namespace std;

#define X                   first
#define Y                   second
#define pb                  push_back
#define mp                  make_pair
#define all(a)              (a).begin(), (a).end()
#define fillchar(a, x)      memset(a, x, sizeof(a))
#define copy(a, b)          memcpy(a, b, sizeof(a))

typedef long long ll;
typedef pair<int, int> pii;
typedef unsigned long long ull;

//#ifndef ONLINE_JUDGE
void RI(vector<int>&a,int n){a.resize(n);for(int i=0;i<n;i++)scanf("%d",&a[i]);}
void RI(){}void RI(int&X){scanf("%d",&X);}template<typename...R>
void RI(int&f,R&...r){RI(f);RI(r...);}void RI(int*p,int*q){int d=p<q?1:-1;
while(p!=q){scanf("%d",p);p+=d;}}void print(){cout<<endl;}template<typename T>
void print(const T t){cout<<t<<endl;}template<typename F,typename...R>
void print(const F f,const R...r){cout<<f<<", ";print(r...);}template<typename T>
void print(T*p, T*q){int d=p<q?1:-1;while(p!=q){cout<<*p<<", ";p+=d;}cout<<endl;}
//#endif
template<typename T>bool umax(T&a, const T&b){return b<=a?false:(a=b,true);}
template<typename T>bool umin(T&a, const T&b){return b>=a?false:(a=b,true);}

const double PI = acos(-1.0);
const int INF = 1e9 + 7;
const double EPS = 1e-12;

/* -------------------------------------------------------------------------------- */

const int maxn = 1e6 + 7;

pii E[maxn * 2];
int SZ;
int Next[maxn * 2];
int last[maxn];
int son[maxn];

void add(int u, int v) {
    E[SZ ++] = mp(u, v);
    E[SZ ++] = mp(v, u);
    Next[SZ - 2] = last[u];
    last[u] = SZ - 2;
    Next[SZ - 1] = last[v];
    last[v] = SZ - 1;
}

int vis[maxn], dp[maxn][2];

void dfs(int rt) {
    vis[rt] = true;
    int ans = 0, minv1 = INF, minv2 = INF, sum = 0, sum1 = 0, cnt = 0;
    for (int i = last[rt]; ~i; i = Next[i]) {
        int v = E[i].Y;
        if (!vis[v]) {
            dfs(v);
            cnt ++;
            sum += dp[v][0];
            sum1 += dp[v][1];
            int buf = dp[v][1] - dp[v][0];
            if (buf < minv1) {
                minv2 = minv1;
                minv1 = buf;
            }
            else {
                if (buf < minv2) minv2 = buf;
            }
        }
    }
    if (cnt == 0) dp[rt][0] = dp[rt][1] = 1;
    else if (cnt == 1) dp[rt][0] = dp[rt][1] = sum1;
    else if (cnt >= 2) {
        dp[rt][0] = sum + minv1 + minv2 - 1;
        dp[rt][1] = sum + minv1;
    }
//    printf("%d: %d %d\n", rt, dp[rt][0], dp[rt][1]);
}

int main() {
#ifndef ONLINE_JUDGE
    freopen("in.txt", "r", stdin);
    //freopen("out.txt", "w", stdout);
#endif // ONLINE_JUDGE
    int T;
    cin >> T;
    while (T --) {
        int n;
        cin >> n;
        SZ = 0;
        fillchar(last, - 1);
        fillchar(Next, - 1);
        for (int i = 1; i < n; i ++) {
            int u, v;
            scanf("%d%d", &u, &v);
            add(u, v);
        }
        fillchar(vis, 0);
        dfs(1);
        cout << dp[1][0] * 2 - 1 << endl;
    }
    return 0;
}