HDU 3094 树上删边 NIM变形

基本的树上删边游戏

写过很多遍了

 

/** @Date    : 2017-10-13 18:19:37* @FileName: HDU 3094 树上删边 NIM变形.cpp* @Platform: Windows* @Author  : Lweleth (SoungEarlf@gmail.com)* @Link    : https://github.com/* @Version : $Id$*/
#include <bits/stdc++.h>
#define LL long long
#define PII pair
#define MP(x, y) make_pair((x),(y))
#define fi first
#define se second
#define PB(x) push_back((x))
#define MMG(x) memset((x), -1,sizeof(x))
#define MMF(x) memset((x),0,sizeof(x))
#define MMI(x) memset((x), INF, sizeof(x))
using namespace std;const int INF = 0x3f3f3f3f;
const int N = 1e5+20;
const double eps = 1e-8;vectoredg[N];int dfs(int x, int pre)
{int res = 0;for(auto i : edg[x]){if(i == pre) continue;res ^= 1 + dfs(i, x);}return res;
}int main()
{int T;cin >> T;while(T--){int n;scanf("%d", &n);for(int i = 0; i <= n; i++) edg[i].clear();for(int i = 0; i < n - 1; i++){int x, y;scanf("%d%d", &x, &y);edg[x].PB(y);edg[y].PB(x);}int ans = dfs(1, -1);printf("%s\n", ans?"Alice":"Bob");}return 0;
}