DSA.jAVA.ALGO

If there is no node, 
  create a newNode.
else (a node is already present)
  insert the newNode at the end (last node from left to right.)
  
heapify the arrayIf nodeToBeDeleted is the leafNode
  remove the node
Else swap nodeToBeDeleted with the lastLeafNode
  remove noteToBeDeleted
   
heapify the array
// Priority Queue implementation in Java

import java.util.ArrayList;

class Heap {
  // Function to heapify the tree
  void heapify(ArrayList<Integer> hT, int i) {
    int size = hT.size();
    // Find the largest among root, left child and right child
    int largest = i;
    int l = 2 * i + 1;
    int r = 2 * i + 2;
    if (l < size && hT.get(l) > hT.get(largest))
      largest = l;
    if (r < size && hT.get(r) > hT.get(largest))
      largest = r;

    // Swap and continue heapifying if root is not largest
    if (largest != i) {
      int temp = hT.get(largest);
      hT.set(largest, hT.get(i));
      hT.set(i, temp);

      heapify(hT, largest);
    }
  }

  // Function to insert an element into the tree
  void insert(ArrayList<Integer> hT, int newNum) {
    int size = hT.size();
    if (size == 0) {
      hT.add(newNum);
    } else {
      hT.add(newNum);
      for (int i = size / 2 - 1; i >= 0; i--) {
        heapify(hT, i);
      }
    }
  }

  // Function to delete an element from the tree
  void deleteNode(ArrayList<Integer> hT, int num) {
    int size = hT.size();
    int i;
    for (i = 0; i < size; i++) {
      if (num == hT.get(i))
        break;
    }

    int temp = hT.get(i);
    hT.set(i, hT.get(size - 1));
    hT.set(size - 1, temp);

    hT.remove(size - 1);
    for (int j = size / 2 - 1; j >= 0; j--) {
      heapify(hT, j);
    }
  }

  // Print the tree
  void printArray(ArrayList<Integer> array, int size) {
    for (Integer i : array) {
      System.out.print(i + " ");
    }
    System.out.println();
  }

  // Driver code
  public static void main(String args[]) {

    ArrayList<Integer> array = new ArrayList<Integer>();
    int size = array.size();

    Heap h = new Heap();
    h.insert(array, 3);
    h.insert(array, 4);
    h.insert(array, 9);
    h.insert(array, 5);
    h.insert(array, 2);

    System.out.println("Max-Heap array: ");
    h.printArray(array, size);

    h.deleteNode(array, 4);
    System.out.println("After deleting an element: ");
    h.printArray(array, size);
  }
}