#include <iostream>
#include <iomanip>
#include <ctime>
using namespace std;

// Assumes that value is in the array
int LinearSearch(int *array, int size, int value)
{
  if (size <= 1)
    return 1;

  int i;
  for (i = 0; i < size; i++)
    if (array[i] == value)
      break;

  return i + 1;
}

void Shuffle(int *array, int size)
{
  for (int i = 0; i < size; i++)
  {
    int r = rand() % size;
    int t = array[i];
    array[i] = array[r];
    array[r] = t;
  }
}  

void main(void)
{
  const int SIZE = 10000;
  int a[SIZE];

  srand(time(NULL));

    // Generate array
  for (int i = 0; i < SIZE; i++)
    a[i] = i;

    // Mix it up
  Shuffle(a, SIZE);

    // Search for random numbers (10 sets)
  for (int j = 0; j < 10; j++)
  {
    int total = 0;
    int attempts = 1000;
    for (i = 0; i < attempts; i++)
      total += LinearSearch(a, SIZE, (rand() % SIZE));

    cout << j + 1 << ". Average = " << (double)total / (double)attempts << endl;
  }
} 

Output:

1. Average = 5115.57
2. Average = 5047.94
3. Average = 4915.73
4. Average = 4911.44
5. Average = 4856.43
6. Average = 4920.65
7. Average = 4910.12
8. Average = 4841.81
9. Average = 4860.79
10. Average = 4913.42