Java: Remove a specific element from a stack

Java Stack: Exercise-13 with Solution

Write a Java program to remove a specific element from a stack.

Sample Solution:

Java Code:

import java.util.Scanner;

public class Stack {
  private int[] arr;
  private int top;

  // Constructor to initialize the stack
  public Stack(int size) {
    arr = new int[size];
    top = -1;
  }

  // Method to push an element onto the stack
  public void push(int num) {
    if (top == arr.length - 1) {
      System.out.println("Stack is full");
    } else {
      top++;
      arr[top] = num;
    }
  }

  // Method to pop an element from the stack
  public int pop() {
    if (top == -1) {
      System.out.println("Stack Underflow");
      return -1;
    } else {
      int poppedElement = arr[top];
      top--;
      return poppedElement;
    }
  }

  // Method to get the top element of the stack
  public int peek() {
    if (top == -1) {
      System.out.println("Stack is empty");
      return -1;
    } else {
      return arr[top];
    }
  }

  // Method to check if the stack is empty
  public boolean isEmpty() {
    return top == -1;
  }

  // Method to remove a specific element from the stack
  public void removeElement(int element) {
    int index = -1;
    for (int i = 0; i <= top; i++) {
      if (arr[i] == element) {
        index = i;
        break;
      }
    }

    if (index == -1) {
      System.out.println("Element not found in the stack");
    } else {
      for (int i = index; i < top; i++) {
        arr[i] = arr[i + 1];
      }
      top--;
      System.out.println("Element removed successfully");
    }
  }

  // Method to display the elements of the stack
  public void display() {
    if (top == -1) {
      System.out.println("Stack is empty");
    } else {
      System.out.print("Stack elements: ");
      for (int i = top; i >= 0; i--) {
        System.out.print(arr[i] + " ");
      }
      System.out.println();
    }
  }

  public static void main(String[] args) {
    System.out.println("Initialize a stack:");
    Stack stack = new Stack(5);
    System.out.println("\nInput some elements on the stack:");
    stack.push(1);
    stack.push(2);
    stack.push(3);
    stack.push(4);
    stack.push(5);
    stack.display();
    Scanner scanner = new Scanner(System.in);
    System.out.print("Input an element to remove from the stack: ");
    int element = scanner.nextInt();
    stack.removeElement(element);
    stack.display();
  }
}

Sample Output:

Input some elements on the stack:
Stack elements: 5 4 3 2 1
Input an element to remove from the stack: 3
Element removed successfully
Stack elements: 5 4 2 1

Flowchart:

Live Demo:

Java Code Editor:

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