DS Questions - Question 1

q1.java

package q1;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.EmptyStackException;
import java.util.HashMap;
import java.util.Stack;

public class Main {

	private static HashMap set;

	public static void main(String[] args) {
		set = new HashMap();
		set.put(new Character('}'), new Character('{'));
		set.put(new Character(')'), new Character('('));
		set.put(new Character(']'), new Character('['));
		
		String a = null;
		Stack myStack = new Stack();
		try {
			a = new BufferedReader(new InputStreamReader(System.in)).readLine();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
		boolean isWrong = false;
		for(int i=0;i<a.length();i++){
			Character c = new Character(a.charAt(i));
			
			if (set.containsValue(c)){
				myStack.push(c);
			} else if (set.containsKey(c)){
				Character c2 = null;
				try{
					 c2 = (Character) myStack.pop();
				} catch(EmptyStackException e){
					isWrong = true;
					break;
				}
				if(!c2.equals(set.get(c))){
					isWrong = true;
					break;
				}
			}
		}
		if(!myStack.isEmpty())
			isWrong = true;
		
		if(isWrong)
			System.out.println("Wrong!");
		else
			System.out.println("Right!");
	}
}