Programa Java para clasificación rápida iterativa

Java

// Java implementation of iterative quick sort
class IterativeQuickSort {
 void swap(int arr[], int i, int j)
 {
  int t = arr[i];
  arr[i] = arr[j];
  arr[j] = t;
 }
 
 /* This function is same in both iterative and
 recursive*/
 int partition(int arr[], int l, int h)
 {
  int x = arr[h];
  int i = (l - 1);
 
  for (int j = l; j <= h - 1; j++) {
   if (arr[j] <= x) {
    i++;
    // swap arr[i] and arr[j]
    swap(arr, i, j);
   }
  }
  // swap arr[i+1] and arr[h]
  swap(arr, i + 1, h);
  return (i + 1);
 }
 
 // Sorts arr[l..h] using iterative QuickSort
 void QuickSort(int arr[], int l, int h)
 {
  // create auxiliary stack
  int stack[] = new int[h - l + 1];
 
  // initialize top of stack
  int top = -1;
 
  // push initial values in the stack
  stack[++top] = l;
  stack[++top] = h;
 
  // keep popping elements until stack is not empty
  while (top >= 0) {
   // pop h and l
   h = stack[top--];
   l = stack[top--];
 
   // set pivot element at it's proper position
   int p = partition(arr, l, h);
 
   // If there are elements on left side of pivot,
   // then push left side to stack
   if (p - 1 > l) {
    stack[++top] = l;
    stack[++top] = p - 1;
   }
 
   // If there are elements on right side of pivot,
   // then push right side to stack
   if (p + 1 < h) {
    stack[++top] = p + 1;
    stack[++top] = h;
   }
  }
 }
 
 // A utility function to print contents of arr
 void printArr(int arr[], int n)
 {
  int i;
  for (i = 0; i < n; ++i)
   System.out.print(arr[i] + " ");
 }
 
 // Driver code to test above
 public static void main(String args[])
 {
  IterativeQuickSort ob = new IterativeQuickSort();
  int arr[] = { 4, 3, 5, 2, 1, 3, 2, 3 };
  ob.QuickSort(arr, 0, arr.length - 1);
  ob.printArr(arr, arr.length);
 }
}
/*This code is contributed by Rajat Mishra */