Merge pull request #915 from skmodi649/Add-StackSorting.java

Create StackSorting.java

Java/Data-Structures/Stack/stack/StackSorting.java

@@ -0,0 +1,71 @@
+//This code sorts the Stack in such a way that greatest element is at the top of the stack
+
+/** Problem : Sort the Stack elements such that the greatest element is at the top of the stack
+ * Author : https://github.com/skmodi649
+ */
+
+
+
+package stack;
+import java.util.Scanner;
+import java.util.Stack;
+
+class StackSorting{
+    public static void main(String[] args){
+        Scanner sc=new Scanner(System.in);
+        System.out.println("Enter the Stack size : ");
+        Stack<Integer> s=new Stack<>();
+        int n=sc.nextInt();
+        System.out.println("Enter the elements in the Stack : ");
+        while(n-->0)
+            s.push(sc.nextInt());
+            StackSorting g = new StackSorting();
+            System.out.println("Sorted Stack : ");
+            Stack<Integer> a = g.sort(s);       //Sorted elements inserted in new Stack
+            while (!a.empty()) {
+                System.out.print(a.peek() + " ");
+                a.pop();                          //Popping top elements of the stack
+            }
+}
+
+    public void sortedInsert(Stack<Integer> S , int element)  // This method inserts the sorted element
+    {
+        if((S.empty()) || (S.peek() < element))
+            S.push(element);
+        else
+        {
+            int temp = S.pop();
+            sortedInsert(S , element);
+            S.push(temp);
+        }
+    }
+    public Stack<Integer> sort(Stack<Integer> s)    //Sorts the stack and then returns it
+    {
+        if(!s.empty())
+        {
+            int temp = s.pop();
+            sort(s);
+            sortedInsert(s , temp);
+        }
+        return s;
+    }
+}
+
+
+
+/** Expected Time Complexity: O(N*N)
+ * Expected Auxiliary Space Complexity : O(N)
+ * Constraints : 1<=N<=100
+ */
+
+
+/** Test Case 1 :
+ * Enter the Stack size : 5
+ * Enter the elements in the Stack : 0 1 2 3 9
+ * Sorted Stack : 9 3 2 1 0
+ *
+ * Test Case 2 :
+ * Enter the Stack size : 6
+ * Enter the elements in the Stack : 3 1 2 9 8 7
+ * Sorted Stack : 9 8 7 3 2 1
+ */