1. Write a java program to reverse word of a stack. Take the input word from the user , insert every
character (from the word) into a stack. The output from the stack should be the same as the input.
1. Push into stack
2. Pop from stack
3. Enqueue into queue
4. Dequeue from queue
5. Push into stack
6. Pop from stack and display
Solution
import java.util.LinkedList;
import java.util.Queue;
import java.util.Scanner;
import java.util.Stack;
public class ReverseStack {
public static void main(String[] args) {
Stack<String> stack = new Stack<String>();
Queue<String> queue = new LinkedList<String>();
Scanner sc = new Scanner(System.in);
String word;
while(true){
//reading word from user
System.out.print("Enter word (exit to stop): ");
word = sc.next();

2. if("exit".equalsIgnoreCase(word))
break;
// pushing into stack
stack.push(word);
}
//popping from stack and enqueue into queue
while(!stack.isEmpty()){
queue.offer(stack.pop());
}
//dequeuing from queue and pushing into staack
while(!queue.isEmpty()){
stack.push(queue.poll());
}
//popping from stack and displaying
while(!stack.isEmpty()){
System.out.println(stack.pop());
}
}
}
/*
Sample output:
Enter word (exit to stop): pravesh
Enter word (exit to stop): cat
Enter word (exit to stop): dog
Enter word (exit to stop): apple
Enter word (exit to stop): bat
Enter word (exit to stop): boll
Enter word (exit to stop): today
Enter word (exit to stop): exit
pravesh
cat
dog
apple
bat
boll
today

3. */