POJ 2599 A funny game

POJ 2599 A funny game

树上的dp博弈，很easy的。

#include<iostream>#include<cstdio>#include<cstring>#include<cmath>#include<algorithm>#include<vector>#include<set>#include<queue>#include<map>using namespace std;#define FOR(i,a,b) for(int (i)=(a);(i)<=(b);(i)++)#define DOR(i,a,b) for(int (i)=(a);(i)>=(b);(i)--)#define CLR(a) memset((a),0,sizeof((a)))#define pb push_back#define mp make_pair#define ins insert#define F first#define S second#define bug puts("Oh Here!");#define nMax 2010#define oo 0x7fffffff#define eps 1e-8#define LL long long#define Vec vector<int>#define Pai pair<int,int>class Tree{public:    int first[nMax],nxt[nMax],to[nMax],e;    int vis[nMax],n,win[nMax],place[nMax];    void init(){        memset(first,-1,sizeof(first));        memset(vis,0,sizeof(vis));        memset(place,-1,sizeof place );        e=0;    }    void addadge(int u,int v){        to[e]=v;nxt[e]=first[u];first[u]=e;e++;        to[e]=u;nxt[e]=first[v];first[v]=e;e++;    }    void dfs(int u){        win[u]=0;        vis[u]=1;        for(int i=first[u];i!=-1;i=nxt[i])if(!vis[to[i]]){            dfs(to[i]);            if(win[to[i]]==0) {                win[u]=1;                if(place[u]==-1 || place[u]>to[i]) place[u]=to[i];            }        }        return ;    }};void sovle(int n,int k){    Tree p;    p.n=n;    p.init();    for(int i=1,u,v;i<n;i++) {        scanf("%d%d",&u,&v);        p.addadge(u,v);    }    p.dfs(k);    if(p.win[k]){        printf("First player wins flying to airport %d\n",p.place[k]);    }else {        printf("First player loses\n");    }}int main(){#ifndef ONLINE_JUDGE//    freopen("input.txt","r",stdin);#endif    int n,k;    while(~scanf("%d%d",&n,&k)){        sovle(n,k);    }    return 0;}