CSC-220 In class Stack Exercise

Palindrome.java

import stack.*;

public class Palindrome {

	public static void main(String[] args) {
        // should return true
        System.out.println(checkForPalindrome("abccba"));
        // should return true
        System.out.println(checkForPalindrome("Was it a car or a cat I saw?"));
        // should return true
        System.out.println(checkForPalindrome("I did, did I?"));
        // should return false
        System.out.println(checkForPalindrome("hello"));
        // should return true
        System.out.println(checkForPalindrome("Don't nod"));
	}

    public static boolean checkForPalindrome(String str) {
        str = str.toLowerCase();
        
        Stack<Character> charStack = new Stack<Character>();
        
        String strForward = "";
        for (int i = 0; i < str.length(); i++) {
        	char ch = str.charAt(i);
        	if (ch >= 'a' && ch <= 'z') {
        		strForward += ch;
        		charStack.push(ch);
        	}
        }
        
        String strBackward = "";
        while (!charStack.isEmpty())
        	strBackward += charStack.pop();
        
        return strForward.equals(strBackward);        
    }
}

Palindrome2.java

import stack.*;

public class Palindrome2 {

	public static void main(String[] args) {
        // should return true
        System.out.println(checkForPalindrome("abccba"));
        // should return true
        System.out.println(checkForPalindrome("Was it a car or a cat I saw?"));
        // should return true
        System.out.println(checkForPalindrome("I did, did I?"));
        // should return false
        System.out.println(checkForPalindrome("hello"));
        // should return true
        System.out.println(checkForPalindrome("Don't nod"));
	}

    public static boolean checkForPalindrome(String str) {
        str = str.toLowerCase();
        
        Stack<Character> charStack = new Stack<Character>();
        
        String strForward = "";
        for (int i = 0; i < str.length(); i++) {
        	char ch = str.charAt(i);
        	if (ch >= 'a' && ch <= 'z') {
        		strForward += ch;
        		charStack.push(ch);
        	}
        }
        
        int i = 0;
        while (!charStack.isEmpty()) {
        	char stackChar = charStack.pop();
        	if (strForward.charAt(i) != stackChar)
        		return false;
        	i++;
        }
        
        return true;        
    }
}

PalindromeStarterCode.java

public class PalindromeStarterCode {

	public static void main(String[] args) {
        // should return true
        System.out.println(checkForPalindrome("abccba"));
        // should return true
        System.out.println(checkForPalindrome("Was it a car or a cat I saw?"));
        // should return true
        System.out.println(checkForPalindrome("I did, did I?"));
        // should return false
        System.out.println(checkForPalindrome("hello"));
        // should return true
        System.out.println(checkForPalindrome("Don't nod"));
	}

    public static boolean checkForPalindrome(String string) {
        return false;
    }
}

Stack.java

// Generic Code Derived from Example StackOfIntegers2b.java

package stack;

import java.util.*;

public class Stack<T> {
	private ArrayList<T> list;

	public Stack() {
		list = new ArrayList<T>(16);
	}

	public T push(T item) {
		list.add(item);
		return item;
	}

	public T pop() {
		if (getSize() <= 0) 
			throw new RuntimeException("Can't pop empty stack.");
		T item = list.get(getSize() - 1);
		list.remove(getSize() - 1);
		return item;
	}

	public T peek() {
		if (getSize() <= 0) 
			throw new RuntimeException("Can't peek empty stack.");
		return list.get(getSize() - 1);
	}

	public boolean isEmpty() {
		return list.isEmpty();
	}

	public int getSize() {
		return list.size();
	}

	public int search(int i) {
		return list.lastIndexOf(i);
	}

	/** Override the toString in the Object class */
	public String toString() {
		return "stack: " + list.toString();
	}
}