JavaScript QuickSelect Algrothm with the help of Meidan of Medians

In computer science, the median of medians is an approximate median selection algorithm, frequently used to supply a good pivot for an exact selection algorithm, most commonly quickselect, that selects the kth smallest element of an initially unsorted array. Median of medians finds an approximate median in linear time. For more information please see: Median of medians.

function median_algorithm(nums, k) {
    const chunkSize = 5;
    let chunks = [];
    let medians = [];
    for(let i=0; i < nums.length; i += chunkSize) {
        // We have to split the list into chunks of 5 items and sort each array
        let chunck = nums.slice(i, i+chunkSize).sort((a, b) => a > b ? 1: -1);
        // the median is the middle item in the sorted order
        const median = chunck[parseInt(chunck.length / 2 , 10)]
        chunks.push(chunck);
        medians.push(median);
    }
    // The median of all medians is the pivot Value
    const pivotValue = medians[parseInt(medians.length / 2 , 10)]
    // Partion Phase (Now Partition the original array into two different array
    const leftArray = nums.filter(num => num < pivotValue);
    const rightArray = nums.filter(num => num > pivotValue);
    // selection Phase
    if(k < leftArray.length) {
        // We have to consider the left array because we are looking for
        // smaller items
        return median_algorithm(leftArray, k)
    } else if (k > leftArray.length) {
        // We have to consider the right array because we are looking for
        // larger items
        return median_algorithm(rightArray, k - leftArray.length - 1)
    } else {
        return pivotValue;
    }
  
}
function select(nums, k) {
    return median_algorithm(nums, k-1);
}



x = [1, -5, 0, 10, 15, 20, 3, -1, 21, 22, 23, 24, 25, 26, 27, 28, 29]
console.log(select(x, 3))