Create Delete_Middle_Element_Stack_Recursion.java

Author: py3-coder

Recursion/Delete_Middle_Element_Stack_Recursion.java

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+import java.util.*;
+//Problem :: Delete a middle ele of Stack :::
+//Using Recursion :::
+
+public class Main
+{
+	public static void main(String[] args) {
+	    Stack<Integer> st = new Stack<>();
+	    st.push(9);
+	    st.push(-4);
+	    st.push(2);
+	    st.push(7);
+	    st.push(11);
+	    
+	    int mid =(st.size()/2)+1;
+	    deleteMidStack(st,mid);
+	    //TC : O(n)
+	    //SC : O(1) 
+	    //Auxillary Space : O(n) -- Recursion Stack
+	    System.out.println(st);
+		
+	}
+	public static void deleteMidStack(Stack<Integer> st,int indx){
+	    //B H I 
+	    //Base case ::
+	    if(indx==1){
+	        st.pop();
+	        return;
+	    }
+	    //Hypothesis:: 
+	    int ele =st.pop();
+	    //Induction:::
+	    deleteMidStack(st,indx-1);
+	    st.push(ele);
+	}
+	
+}