a chess game(博弈sg).cpp

杭电acm解题报告2001---2099.

#include <cstdio>
#include <string>
#include <vector>
#include <algorithm>
using namespace std;

int n,m;
vector<int> tmap[1100];
//vector<int> imap[1100];
int sg[1100];

int dfs(int pos)
{
    int i,j,t;
    if (tmap[pos].size() == 0) {
        sg[pos] = 0;
        return 0;
    }
    bool v[1100];
    memset(v,false,sizeof(v));
    for (i=tmap[pos].size()-1;i>=0;i--) {
        if (sg[ tmap[pos][i] ] == -1) {
            v[ dfs(tmap[pos][i]) ] = true;
        }
        else {
            v[ sg[ tmap[pos][i] ] ] = true;
        }
    }
    for (i=0;i<=n;i++) {
        if (!v[i]) {
            break;
        }
    }
    sg[pos] = i;
    return sg[pos];
}

int main()
{
    while (scanf("%d",&n)==1) {
        int i,j,x,t;
        for (i=0;i<=n;i++) {
            tmap[i].clear();
            //imap[i].clear();
        }
        memset(sg,-1,sizeof(sg));
        for (i=0;i<n;i++) {
            scanf("%d",&x);
            for (j=0;j<x;j++) {
                scanf("%d",&t);
                tmap[i].push_back(t);
                //imap[t].push_back(i);
            }
        }
        for (i=0;i<n;i++) {
            if (sg[i] == -1) {
                dfs(i);
            }
        }
        while (scanf("%d",&m)==1) {
            if (m == 0) {
                break;
            }
            int xor = 0;
            for (i=0;i<m;i++) {
                scanf("%d",&t);
                xor ^= sg[t];
            }
            if (xor == 0) {
                printf("LOSE\n");
            }
            else {
                printf("WIN\n");
            }
        }
    }
}