Stack Data Type

To get a feel for some of the methods of the Stack. Run the code from this webpage.

Strack Programming Exercises

• Exercise 1) Write your own pared down version of the Stack class. This class should have the following methods . Refer to the quick reference to see what these methods should do and return. You may want to use an Object[] array to hold Stack elements. When the array fills up, allocate an array of twice the size and copy the values to the larger array.
  • push(E Object)
  • pop()
  • peek()
  • isEmpty();

Programming Projects involving Stacks

Project 1) Make the isPlandrome() method below work using only 1 Stack and no other data structures

import java.util.Stack;
import java.util.Scanner;
import javax.swing.JOptionPane;

public class Palindrome2Student {

public static Stack<Character>stack= new Stack();

public static void main(String args[]){
String word= JOptionPane.showInputDialog("Type in a potential palindrome");
int lenght;
  
System.out.println(isPalindrome(word));
}

public static boolean isPalindrome(String stringToParse){
	
	
	int length = stringToParse.length();
	
	
	for (int i =0;i < length;i++){
   System.out.println("Pushing in: "+ stringToParse.charAt(i)); 
				
	stack.push(stringToParse.charAt(i));
	
	}
   System.out.println("________________________");
	for (int i =0;i < length;i++){
   System.out.println("Popping out : "+stack.pop()); 

	}
	

	return false;
	}

}
	  

solution

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Project 2) Write a class that ensures that brackets, curley braces and parentheses are properly closed. This class should work for nested delimiters.

Using stack to check matching delimiters

Examples:

c[d] // correct a{b[c]d}e // correct a{b(c]d}e // not correct; ] doesn't match ( a[b{c}d]e} // not correct; nothing matches final } a{b(c) // not correct; Nothing matches opening {

solution