Question

Can Anyone help me to convert Below code to C++!

Thanks

For example, in C++, the function headers would be the following:
class MaxHeap {
vector<int> data;
public:
MaxHeap() {
// ...
}
int size() {
// ...
}
int maxLookup() {
// ...
}
void extractMax() {
// ...
}
void insert(int data) {
// ...
}
void remove(int index) {
// ...
}
};

========================

import java.util.Arrays;
import java.util.Scanner;

public class MaxHeap {
    Integer[] a;
    int size; // size of the heap
    int currentHeight = 1;

    public MaxHeap() {
        a = new Integer[(int) (Math.pow(2, currentHeight) - 1)];
    }

    private void increaseHeight() {

        Integer aNew[] = new Integer[(int) (Math.pow(2, currentHeight + 1) - 1)];

        for(int i=0; i<(int) (Math.pow(2, currentHeight) - 1); i++) {
            aNew[i] = a[i];
        }
        currentHeight++;
        a = aNew;
    }

    public int getSize() {
        return size;
    }

    private int parent(int pos) {
        return (pos - 1)/ 2;
    }

    private int leftChild(int pos) {
        return 2 * pos + 1;
    }

    private int rightChild(int pos) {
        return 2 * pos + 2;
    }

    private boolean isLeaf(int pos) {
        if (pos >= (size / 2) && pos <= size) {
            return true;
        }
        return false;
    }

    private void swap(int fpos, int spos) {
        int tmp;
        tmp = a[fpos];
        a[fpos] = a[spos];
        a[spos] = tmp;
    }

    public void heapify(int pos) {
        if (!isLeaf(pos)) {
            if ((a[leftChild(pos)] != null && a[pos] < a[leftChild(pos)] )||(a[rightChild(pos)] != null &&  a[pos] < a[rightChild(pos)])) {
                if(a[rightChild(pos)] == null) {
                    swap(pos, leftChild(pos));
                    heapify(leftChild(pos));
                } else if(a[leftChild(pos)] == null) {
                    swap(pos, rightChild(pos));
                    heapify(rightChild(pos));
                } else if (a[leftChild(pos)] > a[rightChild(pos)]) {
                    swap(pos, leftChild(pos));
                    heapify(leftChild(pos));
                } else {
                    swap(pos, rightChild(pos));
                    heapify(rightChild(pos));
                }
            }
        }
    }

    public static void main(String[] args) {
        MaxHeap heap = new MaxHeap();

        Scanner in = new Scanner(System.in);

        String line;
        int commands = in.nextInt();

        for(int i=0; i<commands; i++) {
            line = in.nextLine();
            if(line.isEmpty()) {
                i--;
                continue;               
            }

            if(line.equalsIgnoreCase("size")) {
                System.out.println(heap.getSize());
            } else if(line.toLowerCase().startsWith("insert")) {
                heap.insert(Integer.parseInt(line.split(" ")[1]));
            } else if(line.equalsIgnoreCase("maxLookup")) {
                System.out.println(heap.lookup());
            } else if(line.equalsIgnoreCase("extractmax")) {
                heap.extract_max();
            } else if(line.toLowerCase().startsWith("delete")) {
                heap.remove(Integer.parseInt(line.split(" ")[1]));
            }
        }

        in.close();
    }

    public void extract_max() {
        remove(0);      
    }

    public void remove(int index) {
        a[index] = a[--size]; 
        a[size] = null;
        heapify(index);     
    }

    public void insert(Integer element) {
        if(size == (int) (Math.pow(2, currentHeight) - 1)) {
            increaseHeight();
        }

        a[size] = element;
        int current = size;
        size++;

        while (a[current] > a[parent(current)]) {
            swap(current, parent(current));
            current = parent(current);
        }
    }

    public Integer lookup() {
        if (size > 0) {
            return a[0];
        }
        return null;
    }

}

Answer 1

//C++ program

#include<iostream>
#include<math.h>
using namespace std;

class MaxHeap {
   private:
int *a;
int size; // size of the heap
int currentHeight ;
  
void increaseHeight() {

int* aNew = new int [(int)pow(2,currentHeight+1)-1];

for(int i=0; i<(int)pow(2,currentHeight)-1; i++) {
aNew[i] = a[i];
}
currentHeight++;
a = aNew;
}
int parent(int pos) {
return (pos - 1)/ 2;
}
  
int leftChild(int pos) {
return 2 * pos + 1;
}
  
int rightChild(int pos) {
return 2 * pos + 2;
}
  
bool isLeaf(int pos) {
if (pos >= (size / 2) && pos <= size) {
return true;
}
return false;
}
void swap(int fpos, int spos) {
int tmp;
tmp = a[fpos];
a[fpos] = a[spos];
a[spos] = tmp;
}

public :
   MaxHeap() {
       currentHeight=1;
       size = (int)pow(2,currentHeight)-1;
a = new int [(int)pow(2,currentHeight)-1];
}

int getSize() {
return size;
}

void heapify(int pos) {
if (!isLeaf(pos)) {
if ((leftChild(pos) < size && a[pos] < a[leftChild(pos)] )||(rightChild(pos) <size && a[pos] < a[rightChild(pos)])) {
if(rightChild(pos)>=size) {
swap(pos, leftChild(pos));
heapify(leftChild(pos));
} else if(leftChild(pos) >=size) {
swap(pos, rightChild(pos));
heapify(rightChild(pos));
} else if (a[leftChild(pos)] > a[rightChild(pos)]) {
swap(pos, leftChild(pos));
heapify(leftChild(pos));
} else {
swap(pos, rightChild(pos));
heapify(rightChild(pos));
}
}
}
}

void extract_max() {
remove(0);
}

void remove(int index) {
a[index] = a[--size];
heapify(index);   
}

void insert(int element) {
if(size == (int) (pow(2, currentHeight) - 1)) {
increaseHeight();
}

a[size] = element;
int current = size;
size++;

while (a[current] > a[parent(current)]) {
swap(current, parent(current));
current = parent(current);
}
}

int lookup() {
if (size > 0) {
return a[0];
}
  
}

};

int main() {
MaxHeap heap ;
       int num;
string line;
int commands ;
cin>>commands;

for(int i=0; i<commands; i++) {
cin>>line;
if(line=="") {
i--;
continue;   
}

if(line=="size") {
cout<<heap.getSize()<<"\n";
} else if(line=="insert") {
   cout<<"Enter number : ";
   cin>>num;
heap.insert(num);
} else if(line=="maxLookup") {
cout<<heap.lookup()<<endl;;
} else if(line=="extractmax") {
heap.extract_max();
} else if(line=="delete") {
   cout<<"Enter number : ";
   cin>>num;
heap.remove(num);
}
}

return 0;
}