StudentHeap.java

import java.util.*;

class StudentHeap {
  
    // To heapify a subtree rooted with node i
    // which is an index in arr[].
    static void heapify(int arr[], int n, int i) {
        int largest = i; 
        int l = 2 * i + 1; 
        int r = 2 * i + 2;

        if (l < n && arr[l] > arr[largest]) {
            largest = l;
        }

        if (r < n && arr[r] > arr[largest]) {
            largest = r;
        }

        if (largest != i) {
            int temp = arr[i];
            arr[i] = arr[largest];
            arr[largest] = temp;
            heapify(arr, n, largest);
        }
    }

    static void heapSort(int arr[]) {
        int n = arr.length;

        for (int i = n / 2 - 1; i >= 0; i--) {
            heapify(arr, n, i);
        }

        System.out.println("Max Heap:");
        printArray(arr);
        
        System.out.println("Highest-ranked student: " + arr[0]);

        for (int i = n - 1; i > 0; i--) {
            int temp = arr[0]; 
            arr[0] = arr[i];
            arr[i] = temp;
            heapify(arr, i, 0);
        }
    }

    static void printArray(int arr[]) {
        for (int i = 0; i < arr.length; i++) {
            System.out.print(arr[i] + " ");
        }
        System.out.println();
    }

    public static void main(String args[]) {
        Scanner sc = new Scanner(System.in);
        
        System.out.println("Enter the number of students:");
        int n = sc.nextInt();
        int arr[] = new int[n];
        
        System.out.println("Enter the scores of students:");
        for (int i = 0; i < n; i++) {
            arr[i] = sc.nextInt();
        }
        
        heapSort(arr);
        System.out.println("Sorted array is ");
        printArray(arr);
        
        sc.close();
    }
}