#include <iostream>
#include <cstdlib>
#include <time.h>

using namespace std;

//function prototypes
void randomize(int ar[], int n);
void printArray(int ar[], int n);

int main(void) {
  int nums[] = { 1, 2, 3, 4, 5, 6, 7};
  int n = sizeof(nums) / sizeof(nums[0]);   //find the number of elements

  //seed the PRNG
  srand(time(0));

  //print the orderings of the array
  printArray(nums, n);
  randomize(nums, n);
  printArray(nums, n);
  randomize(nums, n);
  printArray(nums, n);

  return 0;
}


void
randomize(int ar[], int n) {
  int i, d, tmp;

  for(i=0; i<n; i++) {
    d = rand() %n;
    
    //swap element i and element d
    tmp = ar[i];
    ar[i] = ar[d];
    ar[d] = tmp;
  }
}

void
printArray(int ar[], int n) {
  cout << "{";
  
  for(int i=0; i<n; i++) {
    //put a separator between the array elements
    if(i!=0)
      cout << ", ";
    cout << ar[i];
  }
  cout << "}" << endl;
}