stack reverse recurssion

joharbatta · joharbatta · commit 4a87f9cc246d · 2020-03-16T01:47:16.000+05:30
diff --git a/Stack/stackReverse.java b/Stack/stackReverse.java
@@ -1,19 +1,45 @@
 import java.util.*;
+import java.util.Stack;
 class stackReverse {
 
+	static Stack<Character> s=new Stack<>();
+	static void reverse()
+	{
+		if(s.isEmpty())
+		{
+			return;
+		}
+		char a=s.pop();
+		reverse();
+		insertBottom(a);
+	}
+	static void insertBottom(char a)
+	{
+		if(s.isEmpty())
+		{
+			s.push(a);
+			return;
+		}
+		char b=s.pop();
+		insertBottom(a);
+		s.push(b);
+
+	}
 	public static void main(String[] args) {
 	
-		Stack <Character> s = new Stack <Character>();
 			Scanner in = new Scanner(System.in);
-			String ans = "", data = in.nextLine();
+			// String ans = "",
+			String data = in.nextLine();
 			
-	        for (char element : data.toCharArray()) {
+			for (char element : data.toCharArray()) 
+			{
 	            s.push(element);
 	        }
-	        for (char element : data.toCharArray()) {
-	            ans += s.pop();
-	        }
-	        System.out.print(ans);
+			reverse();
+	        // for (char element : data.toCharArray()) {
+	        //     ans += s.pop();
+	        // }
+	        System.out.print(s);
 	}
 
 }
