最后一块石头

 Arrays.sort(stones);
        int len = stones.length;
        if(len == 0){
            return 0;
        }
        if(len == 1){
            return 1;
        }
            while(stones[len-1] != 0 ){
            if(stones[len-1] == 0){
                break;
            } 
            if(stones[len-1] != 0 && stones[len-1-1] == 0){
                break;
            }
            if(stones[len-1] == stones[len-1-1]){
                stones[len-1] =0;
                stones[len-1-1] = 0;
            } else {
                stones[len-1-1] = stones[len-1] - stones[len-1-1];
                stones[len-1] = 0;
               
            }
             Arrays.sort(stones);
        }
        
        return stones[len - 1];