Heap sort

#include <iostream>
using namespace std;

void heapsort(int arr[], unsigned int N)
{
	unsigned int n = N, i = n/2, parent, child;
	int t;

	for (;;) { /* Loops until arr is sorted */
	  if (i > 0) { /* First stage - Sorting the heap */
	      i--;           /* Save its index to i */
	      t = arr[i];    /* Save parent value to t */
	  } else {     /* Second stage - Extracting elements in-place */
	      n--;           /* Make the new heap smaller */
	      if (n == 0) return; /* When the heap is empty, we are done */
	      t = arr[n];    /* Save last value (it will be overwritten) */
	      arr[n] = arr[0]; /* Save largest value at the end of arr */
	  }

	  parent = i; /* We will start pushing down t from parent */
	  child = i*2 + 1; /* parent's left child */

	  /* Sift operation - pushing the value of t down the heap */
	  while (child < n) {
	      if (child + 1 < n  &&  arr[child + 1] > arr[child]) {
		  child++; /* Choose the largest child */
	      }
	      if (arr[child] > t) { /* If any child is bigger than the parent */
		  arr[parent] = arr[child]; /* Move the largest child up */
		  parent = child; /* Move parent pointer to this child */
		  //child = parent*2-1; /* Find the next child */
		  child = parent*2+1; /* the previous line is wrong*/
	      } else {
		  break; /* t's place is found */
	      }
	  }
	  arr[parent] = t; /* We save t in the heap */
	}
}

int main(int argc, char* argv[])
{

    return 0;
}