LEARNING JOURNAL

function sortArray(nums: number[]):number[] {
    const aux = Array(nums.length);

    for(let sz = 1; sz < nums.length; sz+= sz) {
        for(let lo = 0; lo < nums.length - sz; lo+= 2*sz) {
            merge(nums, aux, lo, lo + sz -1, Math.min(lo+ 2*sz -1, nums.length -1));
        }
    }

    return nums;
}

function merge(a:number[], aux:number[], lo:number, mid:number, hi:number) {
    for(let i = lo; i <=hi; i++) {
        aux[i] = a[i];
    }

    let lowI = lo, highI = mid + 1;


    for(let i = lo; i <= hi; i++) {
        if(lowI > mid) a[i] = aux[highI++];
        else if(highI > hi) a[i] = aux[lowI++];
        else if(aux[lowI] < aux[highI]) a[i] = aux[lowI++];
        else a[i] = aux[highI++];
        
    }


}