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MaxHeap.cpp
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MaxHeap.cpp
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// Implementation of MaxHeap with Insertion and Deletion Function
#include <iostream>
using namespace std;
// To heapify a subtree rooted with node i which is
// an index of arr[] and n is the size of heap
void heapify(int arr[], int n, int i)
{
int largest = i; // Initialize largest as root
int l = 2 * i + 1; // left = 2*i + 1
int r = 2 * i + 2; // right = 2*i + 2
// If left child is larger than root
if (l < n && arr[l] > arr[largest])
largest = l;
// If right child is larger than largest so far
if (r < n && arr[r] > arr[largest])
largest = r;
// If largest is not root
if (largest != i) {
swap(arr[i], arr[largest]);
// Recursively heapify the affected sub-tree
heapify(arr, n, largest);
}
}
// Function to delete the root from Heap
void deleteRoot(int arr[], int& n)
{
// Get the last element
int lastElement = arr[n - 1];
// Replace root with last element
arr[0] = lastElement;
// Decrease size of heap by 1
n = n - 1;
// heapify the root node
heapify(arr, n, 0);
}
// Function to insert a new node to the Heap
void insertNode(int arr[], int& n)
{
int key;
cout << "Enter the key to be inserted:" << endl;
cin >> key;
// Increase the size of Heap by 1
n = n + 1;
// Insert the element at end of Heap
arr[n - 1] = key;
// Heapify the new node following a
// Bottom-up approach
heapify(arr, n, n - 1);
}
/* A utility function to print array of size n */
void printArray(int arr[], int n)
{
for (int i = 0; i < n; ++i)
cout << arr[i] << " ";
cout << "\n";
}
int main()
{
cout << "Enter the size of the array:" ;
int n;
cin >> n;
cout << "Enter the elements of the array: ";
int arr[n];
for(int i=0;i<n;i++)
{
cin >> arr[i];
}
int t;
while(t!=4)
{
cout << " Press 1 to delete a node.\n Press 2 to insert a node.\n Press 3 to print modified Array.\n Press 4 to exit tge program.\n";
cin >> t;
if(t==1) deleteRoot(arr,n);
else if(t==2) insertNode(arr,n);
else if(t==3) printArray(arr,n);
else if(t==4) break;
else cout << "\nWrong Option chosen" << endl;
}
return 0;
}