289.cpp

//
//  289.cpp
//  leetcode
//
//  Created by R Z on 2018/4/9.
//  Copyright © 2018年 R Z. All rights reserved.
//

#include <stdio.h>
#include <vector>
using namespace std;
class Solution {
public:
    void gameOfLife(vector<vector<int>>& board) {
        int m=board.size(), n=m?board[0].size():0;
        for(int i=0; i<m; i++){
            for(int j=0; j<n; j++){
                int count = 0;
                for(int I=max(i-1,0); I<min(i+2,m); I++){
                    for(int J=max(j-1,0); J<min(j+2,n); J++){
                        count+=board[I][J]&1;
                    }
                }
                if(count==3 || count-board[i][j]==3){
                    board[i][j] |= 2;
                }
            }
        }
        for(int i=0; i<m; i++){
            for(int j=0; j<n; j++){
                board[i][j]>>=1;
            }
        }
    }
};