POJ2311——Cutting Game(sg函数)

Cutting Game

Time Limit: 1000MS Memory Limit: 65536KTotal Submissions: 3859 Accepted: 1438

Description

Urej loves to play various types of dull games. He usually asks other people to play with him. He says that playing those games can show his extraordinary wit. Recently Urej takes a great interest in a new game, and Erif Nezorf becomes the victim. To get away from suffering playing such a dull game, Erif Nezorf requests your help. The game uses a rectangular paper that consists of W*H grids. Two players cut the paper into two pieces of rectangular sections in turn. In each turn the player can cut either horizontally or vertically, keeping every grids unbroken. After N turns the paper will be broken into N+1 pieces, and in the later turn the players can choose any piece to cut. If one player cuts out a piece of paper with a single grid, he wins the game. If these two people are both quite clear, you should write a problem to tell whether the one who cut first can win or not.

Input

The input contains multiple test cases. Each test case contains only two integers W and H (2 <= W, H <= 200) in one line, which are the width and height of the original paper.

Output

For each test case, only one line should be printed. If the one who cut first can win the game, print "WIN", otherwise, print "LOSE".

Sample Input

2 23 24 2

Sample Output

LOSELOSEWIN

也就是一个分解子游戏的过程

#include<iostream>#include<cstdio>#include<algorithm>#include <queue>#include<cstring>#include <vector>#include <set>using namespace std;const int MAXN = 200 + 10;//记忆化搜索所用函数，初始化为-1int mem[MAXN][MAXN];//计算当前状态sg值int sg(int w,int h){    if(mem[w][h]!=-1)        return mem[w][h];    int vis[2000];    memset(vis,0,sizeof(vis));    //竖着切    //把切下来的两张纸看作是两个游戏    //则sg值可以看作是sg1^sg2    //也就是说sg值的异或值等于多个游戏的复合状态    for(int i=2;w-i>=2;i++)        vis[sg(i,h)^sg(w-i,h)]=1;    //横着切    for(int i=2;h-i>=2;i++)        vis[sg(w,i)^sg(w,h-i)]=1;    int i=0;    for(;;i++)        if(vis[i]==0)            return mem[w][h]=i;}int main(){    int w,h;    //一定要放在循环外面！要不然会T    memset(mem,-1,sizeof(mem));    while(scanf("%d%d",&w,&h)!=EOF){        if(sg(w,h)!=0)            puts("WIN");        else            puts("LOSE");    }    return 0;}