JS中的快速选择

Question

数组中的第 K 个最大元素，我坚持使用基本情况。 考虑到 lastElement 是最佳选择，我想我找到枢轴的逻辑是正确的，任何人都可以帮助我解决某些输入的无限问题。

const swap = function(arr,id1,id2){
    const temp = arr[id1];
    arr[id1] = arr[id2];
    arr[id2] = temp;
};

const pivot = function(nums){

    let firstIdx = 0;
    let lastIdx = nums.length-1;

    // lets consider last element
    for(let i = firstIdx ; i< lastIdx;i++){
        if(nums[i] > nums[lastIdx]){
            swap(nums,firstIdx,i);
            firstIdx++;
        }
    }
    swap(nums,firstIdx,lastIdx);
    
    return firstIdx;
}



const kThLargestElement = function(nums, m){


    if(nums.length === 1) return nums[0];
    let guess = pivot(nums);
    //console.log(`guess : ${guess},m: ${m},nums: ${nums}`);
    
    if(guess > m) return kThLargestElement(nums.slice(0,guess),m);
    if(guess < m) return kThLargestElement(nums.slice(guess+1,nums.length),m);
   
    return nums[m];


}

const selection = function(arr,k){
    return kThLargestElement(arr,k-1);
}

console.log(selection([6,-2,1,8,7,5],6));
 //console.log(pivot([6,-2,1,8,7,5]));