// const myArray = [2, 4, 1, 6, -7, 8, 5, 9, 3, 4];

const mergeSort = (arr) => {

if (arr.length <= 1) {

return arr;

}

let midIdx = Math.floor(arr.length / 2);

let left = arr.slice(0, midIdx);

let right = arr.slice(midIdx);

let leftSorted = mergeSort(left);

let rightSorted = mergeSort(right);

return merge(leftSorted, rightSorted);

};

const merge = (arr1, arr2) => {

let merged = [];

while (arr1.length && arr2.length) {

if (arr1[0] < arr2[0]) {

merged.push(arr1.shift());

} else {

merged.push(arr2.shift());

}

}

return [...merged, ...arr1, ...arr2];

};

//example Usage:

// let myArray = [2, 4, 1, 6, -7, 8, 5, 9, 3, 4];

// console.log(mergeSort(myArray));