sorting algo

/*
Merge Sort 

1. Declare left and right variable , where left = 0 , right = n-1.
2. find mid , which is left+right/2
3. Call recursively mergeSort on (left,mid) and (mid+1,rear)
4. 3rd step will continue till left<right.
5. Then we will call merge on the 2 subproblems.

*/


#include <bits/stdc++.h>
#include<iostream>
using namespace std;
void merge(int arr[], int left, int mid, int right) {

    int len1 = mid - left + 1;
    int len2 = right - mid;

    int leftArr[len1];
    int rightArr[len2];

    for (int i = 0; i < len1; i++)
      leftArr[i] = arr[left + i];
    for (int j = 0; j < len2; j++)
      rightArr[j] = arr[mid + 1 + j];

    int i, j, k;
    i = 0;
    j = 0;
    k = left;

    while (i < len1 && j < len2) {
      if (leftArr[i] <= rightArr[j]) {
        arr[k] = leftArr[i];
        i++;
      } else {
        arr[k] = rightArr[j];
        j++;
      }
      k++;
    }

    while (i < len1) {
      arr[k] = leftArr[i];
      i++;
      k++;
    }

    while (j < len2) {
      arr[k] = rightArr[j];
      j++;
      k++;
    }
  }

void algorithm(int arr[],int left,int right){
        if (left < right) {
      int mid = left + (right-left)/2;

      algorithm(arr, left, mid);
      algorithm(arr, mid + 1, right);

      merge(arr, left, mid, right);
}
    
    
}

int main() {
    int arr[] = {83,1,45,95,45,52,11,47,0,45,67,82};
    int n = sizeof(arr)/sizeof(arr[0]);
    int left = 0;
    int right = n-1;
    algorithm(arr,left,right);
   for(int n : arr)
    cout<<n<<" ";
    return 0;
}