SOURCE

let arr = [2, 1, 4, 2, 15,32,33,21,1]

function insert(arr) {
    if (!arr || arr.length < 2 ) {
        return arr
    }
    let newArr = [arr[0]]
    for(let i = 1; i < arr.length; i++) {
        if (arr[i] <= newArr[0]) {
            newArr.unshift(arr[i])
            continue
        }
        for(let k =newArr.length-1; k >= 0; k--) {
            if(arr[i] > newArr[k]) {
                newArr.splice(k+1, 0, arr[i])
                break
            }
        }
    }
    return newArr
}
console.log(insert(arr))
console.log(quick(arr))

function quick(arr) {
    if (!arr || arr.length < 2 ) {
        return arr
    }
    let mid = Math.round(arr.length/2)
    const midItem = arr.splice(arr, 1)[0]
    let left = []
    let right = []
    for(let i = 0; i < arr.length; i++) {
        if(arr[i] < midItem) {
            left.push(arr[i])
        } else {
            right.push(arr[i])
        }
    }
    return quick(left).concat(midItem,quick(right))
}