题解 | #农场的奶牛分组#

import java.util.*;


public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param weights int整型一维数组 
     * @return bool布尔型
     */

    public boolean fang(int index,int res,int []weights,int sum){

        if(index >= weights.length) return false;

        sum += weights[index];

        if(sum == res) return true;

        if(fang(index+1,res,weights,sum)){
            return true;
        }

        if(fang(index+1,res,weights,sum - weights[index])){
            return true;
        }

        return false;
    }

    public boolean canPartition (int[] weights) {
        // write code here

        int sum = 0;
        for(int i = 0;i<weights.length;i++){
            sum+=weights[i];
        }

        int res = sum/2;
        if(res * 2 != sum){
            return false;
        }

        return fang(0,res,weights,0);
    }
}