Implement Insertion sort in C/C++

Insertion sort is a simple sorting algorithm: a comparison sort in which the sorted array (or list) is built one entry at a time. It is much less efficient on large lists than more advanced algorithms such as quicksort, heapsort, or merge sort.

#include <iostream>
#include <cstdlib>
using namespace std;

void InsertionSort(int* ar, int len);

const int LENGTH = 10;
int data[LENGTH];

int main()
{
  //Prepare data
  for (int i = 0; i < 10; i++) {
      data[i] = rand() % 100;
  }

  cout << "data before Insertion Sort:" << endl;
  for (int i = 0; i < 10; i++)
      cout << data[i] << " ";
  cout << endl << endl;

  InsertionSort(data, LENGTH);

  cout << endl << "data before Insertion Sort:" << endl;
  for (int i = 0; i < 10; i++)
      cout << data[i] << " ";
  cout << endl;

  return 0;
}

void InsertionSort(int* ar, int len){
  int cur, j;

  for (int i = 1; i < len; i++) {
      cur = ar[i];
      j = i - 1;
      while ((j >= 0) && (ar[j] > cur)) {
          ar[j + 1] = ar[j];
          j--;
      }
      ar[j + 1] = cur;

      for (int ii = 0; ii < 10; ii++)
          cout << ar[ii] << " ";
      cout << endl;
  }
}