void MergeSort(vector<int>& arr, int left, int right) {

if (right - left == 1) return;

int mid = (left + right) / 2;

MergeSort(arr, left, mid);

MergeSort(arr, mid, right);

vector<int> tempArray(arr.size());

int i = left, j = mid, k = left;

while (i < mid && j < right)

{

if (arr[i] <= arr[j]) tempArray[k++] = arr[i++];

else tempArray[k++] = arr[j++];

}

while (i < mid) tempArray[k++] = arr[i++];

while (j < right) tempArray[k++] = arr[j++];

for (int t = left; t < right; t++) arr[t] = tempArray[t];

}