#include <stdio.h>

void merge(int *array, int low, int middle, int high){
  int left = middle - low + 1;
  int right = high - middle;

  int tmpLeft[left], tmpRight[right];

  for(int i = 0; i < left; i++){
    tmpLeft[i] = array[low + i];
  }

  for(int j = 0; j < right; j++){
    tmpRight[j] = array[middle + 1+ j];
  }

  int i = 0;
  int j = 0;
  int k = low;

  while(i < left && j < right){
    if (tmpLeft[i] <= tmpRight[j]){
      array[k] = tmpLeft[i];
      i++;
    }
    else{
      array[k] = tmpRight[j];
      j++;
    }
    k++;
  }

  while(i < left){
    array[k] = tmpLeft[i];
    i++;
    k++;
  }

  while(j < right){
    array[k] = tmpRight[j];
    j++;
    k++;
  }
}

void mergeSort(int array[], int low, int high){
  if (low < high){
    int middle = (low + high) / 2;
    mergeSort(array, low, middle);
    mergeSort(array , middle + 1, high);
    merge(array, low, middle, high);
    }
  }


int main(){

    int array[] = {10,7,3,9,18,-4,67,32,0,21};
    int size = sizeof array / sizeof array[0];
    int high = size - 1;
    int low = 0;
    printf("\n");
    printf("%s", "Original Array: \n");
    for(int i = 0; i < size; i++) {
      printf("%d ",array[i]);
    }

    printf("\n");
    printf("\n");
    printf("%s", "Sorted Array:\n");

    mergeSort(array,low,high);

    for(int i = 0; i < size; i++) {
      printf("%d ",array[i]);
    }

  return 0;
}