1561. The maximum number of coins you can get

LeetCode: 1561. The maximum number of coins you can get

1. Sort from small to large.
2. Method 1: 从n/3的位置开始，隔一个取一个>> The reason for n/3 is to let Bob take the n/3 pile with the least number of coins in all piles
3. Method 2: Take two for the largest, one for the smallest, and then take the second largest.

    /**
     *  n / 3
     * @param piles
     * @return
     */
    public int maxCoins(int[] piles) {
    
    
        int ans = 0;
        int len = piles.length ;
        Arrays.sort(piles);
        for (int i = len / 3; i < len; i += 2) {
    
    
            ans += piles[i];
        }
        return ans;
    }

    /**
     *  每次将最大的两个取出来，最小的一个取出来。
     *  ans + 第二大的
     *  @param piles
     * @return
     */
    public int maxCoins2(int[] piles) {
    
    
        int ans = 0;
        // 从小到大排序
        Arrays.sort(piles);
        int len = piles.length - 1;
        for (int i = 0, j = len; i + 1 < j ; i++, j -= 2) {
    
    
            ans += piles[j-1];
        }

        return ans;
    }



    public static void main(String[] args) {
    
    
        int[] n = {
    
    2,4,1,2,7,8};
        B b = new B();
        System.out.println(b.maxCoins(n));
    }