2016多校训练3_1007(hdu5758 Explorer Bo)

 #include <functional>
 #include <algorithm>
 #include <iostream>
 #include <iterator>
 #include <sstream>
 #include <fstream>
 #include <numeric>
 #include <iomanip>
 #include <climits>
 #include <utility>
 #include <complex>
 #include <cstdlib>
 #include <cstring>
 #include <cassert>
 #include <string>
 #include <vector>
 #include <cctype>
 #include <bitset>
 #include <cstdio>
 #include <cmath>
 #include <ctime>
 #include <deque>
 #include <stack>
 #include <queue>
 #include <deque>
 #include <list>
 #include <new>
 #include <map>
 #include <set>
 using namespace std;

 typedef long long LL;
 typedef pair<int, int> PII;
 typedef pair<PII, int> PIII;
 #define PB push_back
 #define FI first
 #define SE second
 #define gcd(x, y) __gcd(x, y)
 #define gcd3(x, y, z) __gcd(__gcd(x, y), z)

 const double EPS = 1e-;
 const double PI = acos(-1.0);
 const int INF = 0x3f3f3f3f;
 const LL INFL = 0x3f3f3f3f3f3f3f3fLL;
 const int MAXN =  + ;
 const int MOD = 1e9 + ;

 int n;
 vector<int> G[MAXN];
 int dp[MAXN][], deg[MAXN], lf[MAXN];

 void dfs(int u, int fa) {
     dp[u][] = lf[u] = ;
     for (int i = , sz = G[u].size(); i < sz; ++i) {
         int v = G[u][i];
         if (v == fa) continue;
         dfs(v, u);
         lf[u] += lf[v];
         int d = (lf[v] & ) ?  : ;
         dp[u][] += dp[v][] + d;
     }
     dp[u][] = INF;
     for (int i = , sz = G[u].size(); i < sz; ++i) {
         int v = G[u][i];
         if (v == fa) continue;
         if (lf[v] == ) dp[u][] = min(dp[u][], dp[u][]);
         int d = (lf[v] & ) ?  : -;
         dp[u][] = min(dp[u][], dp[u][] - dp[v][] + dp[v][] + d);
     }
     if (G[u].size() == ) lf[u] = ;
 }

 int main() {
     int T;
     cin >> T;
     while (T--) {
         scanf("%d", &n);
         for (int i = ; i < MAXN; ++i) {
             G[i].clear();
         }
         memset(dp, , sizeof(dp));
         memset(deg, , sizeof(deg));
         memset(lf, , sizeof(lf));
         for (int i = ; i < n - ; ++i) {
             int u, v;
             scanf("%d%d", &u, &v);
             G[u].PB(v);
             G[v].PB(u);
             deg[u]++;
             deg[v]++;
         }
         if (n == ) {
             puts("");
             continue;
         }
         int leaf = , rt;
         for (int i = ; i <= n; ++i) {
             if (deg[i] == ) {
                 leaf++;
             } else {
                 rt = i;
             }
         }
         dfs(rt, -);
         printf("%d\n", dp[rt][leaf & ]);
     }
     return ;
 }