How to get third largest number in array

gistfile1.txt

#include <assert.h> // for assert
#include <iostream> // for std::cout
#include <climits> // for INT_MAX

int get_third_largest_number(int* arr, int n)
{
  int max1 = -INT_MAX;
  int max2;
  int max3;

  assert(n >= 3);
  for(int i = 0; i < n; i++)
  {
    if(arr[i] > max1)
    {
      max3 = max2;
      max2 = max1;
      max1 = arr[i];
    } else
    if(arr[i] > max2)
    {
      max3 = max2;
      max2 = arr[i];
    } else
    if(arr[i] > max3)
      max3 = arr[i];
  }
  return max3;
}

int main()
{
  int a[] = {1, 2, 3, 4, 5, 6, 7,8 , 9, 10};
  int third = get_third_largest_number(a, 10);
  std::cout << third << std::endl;
  return 0;
}

get_third_largest_number function needs to check if array size(n) is equal or greater than 3, so add assert function at the end of the function body.