From https://www.hackerrank.com/challenges/java-stack/forum Input Format There will be multiple lines in the input file, each having a single non-empty string. You should read input till end-of-file. The part of the code that handles input operation is already provided in the editor. Output Format For each case, print 'true' if the string is bal…

Java Stack.java

import java.util.*;
class Solution{
    
   private static Map<String,String> myMap = createMap();
   private static Map<String,String> createMap() {
       HashMap<String,String> result = new HashMap<String,String>();
       result.put("(",")");
       result.put("[","]");
       result.put("{","}");
       return Collections.unmodifiableMap(result);
   }
   
   public static void main(String []argh)
   {
       Scanner sc = new Scanner(System.in);
      
       while (sc.hasNext()) {
           String input=sc.nextLine();
           Stack myStack = new Stack();          
           String last;
           String next;          
           for (int i=0 ; i<input.length(); i++){
               next = Character.toString(input.charAt(i));                 
               if (myStack.empty()) {
                   myStack.push(next);
               } else {
                   last = myStack.peek().toString();
                   if (myMap.containsKey(last)) {
                       if (myMap.get(last).equals(next)){
                           myStack.pop();
                       } else {
                           myStack.push(next);
                       }
                   } else {
                       myStack.push(next);
                       break;
                   }
               }                 
           }
           System.out.println(myStack.empty());        
       }
   }
}