Bottom-Up Merge Sort

function bottomUpMergeSort(arr, stats) {
  const n = arr.length;
  const tmp = new Array(n);
  for (let width = 1; width < n; width <<= 1) {
    for (let left = 0; left < n; left += width << 1) {
      const mid = Math.min(left + width, n);
      const right = Math.min(left + (width << 1), n);
      let i = left;
      let j = mid;
      let k = left;
      while (i < mid && j < right) {
        compare(i, j);
        if (arr[i] <= arr[j]) tmp[k++] = arr[i++]; else tmp[k++] = arr[j++];
      }
      while (i < mid) {
        tmp[k++] = arr[i++];
      }
      while (j < right) {
        tmp[k++] = arr[j++];
      }
      for (let p = left; p < right; p++) {
        arr[p] = tmp[p];
        write(p, arr[p]);
      }
    }
  }
}

def sort(arr, n, stats):
    tmp = [0] * n
    width = 1
    while (width < n):
        left = 0
        while (left < n):
            mid = min((left + width), n)
            right = min((left + (width << 1)), n)
            i = left
            j = mid
            k = left
            while ((i < mid) and (j < right)):
                if (arr[i] <= arr[j]):
                    tmp[k] = arr[i]
                    k += 1
                    i += 1
                else:
                    tmp[k] = arr[j]
                    k += 1
                    j += 1
            while (i < mid):
                tmp[k] = arr[i]
                k += 1
                i += 1
            while (j < right):
                tmp[k] = arr[j]
                k += 1
                j += 1
            for p in range(left, right):
                arr[p] = tmp[p]
            left += (width << 1)
        width <<= 1

#include <vector>
#include <algorithm>
void sort(std::vector<int>& arr, int n, int& comparisons, int& swaps) {
    std::vector<int> tmp(n);
    for(int width=1; (width < n); width <<= 1) {
        for(int left=0; (left < n); left += (width << 1)) {
            int mid = (((left + width)) < (n) ? ((left + width)) : (n));
            int right = (((left + (width << 1))) < (n) ? ((left + (width << 1))) : (n));
            int i = left;
            int j = mid;
            int k = left;
            while(((i < mid) && (j < right))) {
                if((arr[i] <= arr[j])) {
                    tmp[k++] = arr[i++];
                } else {
                    tmp[k++] = arr[j++];
                }
            }
            while((i < mid)) {
                tmp[k++] = arr[i++];
            }
            while((j < right)) {
                tmp[k++] = arr[j++];
            }
            for(int p=left; (p < right); p++) {
                arr[p] = tmp[p];
            }
        }
    }
}

public void Sort(int[] arr, int n, dynamic stats) {
    int[] tmp = new int[n];
    for(int width=1; (width < n); width <<= 1) {
        for(int left=0; (left < n); left += (width << 1)) {
            int mid = (((left + width)) < (n) ? ((left + width)) : (n));
            int right = (((left + (width << 1))) < (n) ? ((left + (width << 1))) : (n));
            int i = left;
            int j = mid;
            int k = left;
            while(((i < mid) && (j < right))) {
                if((arr[i] <= arr[j])) {
                    tmp[k++] = arr[i++];
                } else {
                    tmp[k++] = arr[j++];
                }
            }
            while((i < mid)) {
                tmp[k++] = arr[i++];
            }
            while((j < right)) {
                tmp[k++] = arr[j++];
            }
            for(int p=left; (p < right); p++) {
                arr[p] = tmp[p];
            }
        }
    }
}

#include <stdio.h>
void sort(int arr[], int n, int* comparisons, int* swaps) {
    int tmp[n];
    for(int width=1; (width < n); width <<= 1) {
        for(int left=0; (left < n); left += (width << 1)) {
            int mid = (((left + width)) < (n) ? ((left + width)) : (n));
            int right = (((left + (width << 1))) < (n) ? ((left + (width << 1))) : (n));
            int i = left;
            int j = mid;
            int k = left;
            while(((i < mid) && (j < right))) {
                if((arr[i] <= arr[j])) {
                    tmp[k++] = arr[i++];
                } else {
                    tmp[k++] = arr[j++];
                }
            }
            while((i < mid)) {
                tmp[k++] = arr[i++];
            }
            while((j < right)) {
                tmp[k++] = arr[j++];
            }
            for(int p=left; (p < right); p++) {
                arr[p] = tmp[p];
            }
        }
    }
}