题解 | #寻找第K大#

/**
 * 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 a int整型一维数组
 * @param n int整型
 * @param K int整型
 * @return int整型
 */

function quickSort(arr) {
    if (arr.length == 0) return null;
    if (arr.length == 1) return arr;

    let mid = Math.floor(arr.length / 2);
    let right = [];
    let left = [];

    for (let i = 0; i < arr.length; i++) {
        if (i === mid) continue;
        // 左边大右边小，从大到小
        arr[i] > arr[mid] ? left.push(arr[i]) : right.push(arr[i]);
    }
    left = quickSort(left);
    right = quickSort(right);
    let result = [arr[mid]];
    result = left ? left.concat(result) : result;
    result = right ? result.concat(right) : result;
    return result;
}

function findKth(a, n, K) {
    // write code here
    if(n<K)return null
    let res = quickSort(a)

    
    return res[K-1]
}
module.exports = {
    findKth: findKth,
};