6451-Add ReverseStringUsingStack.java using Stack data structure

Author: Dhirajgiri18

src/main/java/com/thealgorithms/strings/ReverseStringUsingStack.java

@@ -0,0 +1,49 @@
+package com.thealgorithms.strings;
+
+import java.util.Scanner;
+import java.util.Stack;
+
+public class ReverseStringUsingStack {
+
+    /**
+     * Main method to take user input and print the reversed string.
+     */
+    public static void main(String[] args) {
+
+        // Create a Scanner object to read input from the user
+        Scanner sc = new Scanner(System.in);
+        System.out.print("Enter the String to reverse : ");
+        String str = sc.nextLine();
+
+        // Call the reverse method and print the reversed string
+        System.out.println("Reversed String : " + reverse(str));
+        sc.close();
+
+    }
+
+    /**
+     * Reverses a string using a stack.
+     * 
+     * @param str The input string to reverse
+     * @return The reversed string
+     */
+    public static String reverse(String str) {
+        // StringBuilder to build the reversed string
+        StringBuilder sb = new StringBuilder();
+        // Stack to hold the characters of the string
+        Stack<Character> st = new Stack<>();
+
+        // Push each character of the string onto the stack
+        for (int i = 0; i < str.length(); i++) {
+            st.push(str.charAt(i));
+        }
+
+        // Pop characters from the stack and append to StringBuilder
+        while (!st.empty()) {
+            sb.append(st.pop());
+        }
+        // Convert StringBuilder to String and return
+        String rev = sb.toString();
+        return rev;
+    }
+}