mergeSort

mergeSort.js

function mergeSort(array, half = array.length/2) {
    if(array.length < 2) { return array; }
    const left = array.splice(0, half);
    return merger(mergeSort(left), mergeSort(array));
}
function merger(left, right) {
    const arr = [];
    while(left.length && right.length) {
        if(left[0] < right[0]) {
            arr.push(left.shift());
        } 
        else {
            arr.push(right.shift());
        }
    }
    return [...arr,...left,...right]
}