题解 | #寻找第K大#

import java.util.*;

public class Solution {
    public int findKth(int[] a, int n, int K) {
        // write code here
        quick(a, 0, a.length - 1);
        return a[n-K];
    }

    public static void quick(int[] arr, int l, int r) {
        if (l >= r) return;
        int i = l, j = r;
        while (i < j) {
            while (i < j && arr[j] >= arr[l]) j--;
            while (i < j && arr[i] <= arr[l]) i++;
            swap(arr, i, j);
        }
        swap(arr, i, l);
        quick(arr, l, i - 1);
        quick(arr, i + 1, r);
    }

    public static void swap(int[] arr, int i, int j) {
        int temp = arr[i];
        arr[i] = arr[j];
        arr[j] = temp;
    }
}