Maximum Element Hackerrank Solution Java | Hackerrank Data Structure

 Maximum Element Hackerrank Solution Java

For Explanation Video:

Sample Input

STDIN   Function
-----   --------
10      operations[] size n = 10
1 97    operations = ['1 97', '2', '1 20', ....]
2
1 20
2
1 26
1 20
2
3
1 91
3

Sample Output

26
91

Code:

import java.io.*;

import java.math.*;

import java.security.*;

import java.text.*;

import java.util.*;

import java.util.concurrent.*;

import java.util.function.*;

import java.util.regex.*;

import java.util.stream.*;

import static java.util.stream.Collectors.joining;

import static java.util.stream.Collectors.toList;

public class Solution {

    public static void main(String[] args){

        Scanner scn = new Scanner(System.in);

        int n = scn.nextInt();

        Stack<Integer> st = new Stack<Integer>();

        PriorityQueue<Integer> heap = new PriorityQueue<>(Collections.reverseOrder());

        while(n-->0){

            int t = scn.nextInt();

            switch(t){

                case 1:

                    int num = scn.nextInt();

                    st.push(num);

                    heap.add(num);

                    break;

                case 2:

                    int num1 = st.pop();

                    heap.remove(num1);

                    break;

                case 3:

                    System.out.println(heap.peek());

                    break;

            }

        }

    }

}