Complete PR 1

Exercise_1.cpp

@@ -1,54 +0,0 @@
-#include <bits/stdc++.h> 
-
-using namespace std; 
-
-#define MAX 1000 
-
-class Stack {
-  //Please read sample.java file before starting.
-  //Kindly include Time and Space complexity at top of each file
-    int top; 
-
-public: 
-    int a[MAX]; // Maximum size of Stack 
-
-    Stack() { //Constructor here } 
-    bool push(int x); 
-    int pop(); 
-    int peek(); 
-    bool isEmpty(); 
-}; 
-
-bool Stack::push(int x) 
-{ 
-    //Your code here
-    //Check Stack overflow as well
-} 
-
-int Stack::pop() 
-{ 
-    //Your code here
-    //Check Stack Underflow as well 
-} 
-int Stack::peek() 
-{ 
-    //Your code here
-    //Check empty condition too
-} 
-
-bool Stack::isEmpty() 
-{ 
-    //Your code here 
-} 
-
-// Driver program to test above functions 
-int main() 
-{ 
-    class Stack s; 
-    s.push(10); 
-    s.push(20); 
-    s.push(30); 
-    cout << s.pop() << " Popped from stack\n"; 
-
-    return 0; 
-} 

Exercise_1.java

@@ -1,46 +0,0 @@
-class Stack { 
-    //Please read sample.java file before starting.
-  //Kindly include Time and Space complexity at top of each file
-    static final int MAX = 1000; 
-    int top; 
-    int a[] = new int[MAX]; // Maximum size of Stack 
-
-    boolean isEmpty() 
-    { 
-        //Write your code here 
-    } 
-
-    Stack() 
-    { 
-        //Initialize your constructor 
-    } 
-
-    boolean push(int x) 
-    { 
-        //Check for stack Overflow
-        //Write your code here
-    } 
-
-    int pop() 
-    { 
-        //If empty return 0 and print " Stack Underflow"
-        //Write your code here
-    } 
-
-    int peek() 
-    { 
-        //Write your code here
-    } 
-} 
-
-// Driver code 
-class Main { 
-    public static void main(String args[]) 
-    { 
-        Stack s = new Stack(); 
-        s.push(10); 
-        s.push(20); 
-        s.push(30); 
-        System.out.println(s.pop() + " Popped from stack"); 
-    } 
-}

Exercise_1.js

@@ -1,35 +0,0 @@
-class Stack {
-  //Please read sample.java file before starting.
-  //Kindly include Time and Space complexity at top of each file
-​
-    constructor() {
-        //Initialize your constructor
-        this.MAX = 1000;
-        this.top = -1;
-        this.a = new Array(this.MAX);
-    }
-​
-    function isEmpty() {
-        //Write your code here
-    }
-​
-    function push(x) {
-        //Check for stack Overflow
-        //Write your code here
-    }
-​
-    function pop() {
-        //If empty return 0 and print " Stack Underflow"
-        //Write your code here
-    }
-​
-    function peek() {
-       //Write your code here
-    }
-}
-​
-let s = new Stack();
-s.push(10);
-s.push(20);
-s.push(30);
-console.log(s.pop() + " Popped from stack");

Exercise_1.py

@@ -1,21 +1,31 @@
 class myStack:
   #Please read sample.java file before starting.
   #Kindly include Time and Space complexity at top of each file
-     def __init__(self):
-
+    time :0(1)
+    space:0(n)
+    def __init__(self):
+         self.stack = []
      def isEmpty(self):
-
+         return len(self.stack) == 0
      def push(self, item):
-
+         self.stack.append(item)
      def pop(self):
-
+        if self.isEmpty():
+            print("Stack Underflow")
+            return None
+        return self.stack.pop()
 
      def peek(self):
-
+         if self.isEmpty():
+            print("Stack is Empty")
+            return None
+        return self.stack[-1]
      def size(self):
-
+         return len(self.stack)
      def show(self):
-
+         return self.stack
+
+
 
 s = myStack()
 s.push('1')

Exercise_2.cpp

@@ -1,52 +0,0 @@
-#include <bits/stdc++.h> 
-using namespace std; 
-
-// A structure to represent a stack 
-class StackNode { 
-public: 
-    int data; 
-    StackNode* next; 
-}; 
-
-StackNode* newNode(int data) 
-{ 
-    StackNode* stackNode = new StackNode(); 
-    stackNode->data = data; 
-    stackNode->next = NULL; 
-    return stackNode; 
-} 
-
-int isEmpty(StackNode* root) 
-{ 
-    //Your code here 
-} 
-
-void push(StackNode** root, int data) 
-{ 
-    //Your code here 
-} 
-
-int pop(StackNode** root) 
-{ 
-    //Your code here 
-} 
-
-int peek(StackNode* root) 
-{ 
-    //Your code here 
-} 
-
-int main() 
-{ 
-    StackNode* root = NULL; 
-
-    push(&root, 10); 
-    push(&root, 20); 
-    push(&root, 30); 
-
-    cout << pop(&root) << " popped from stack\n"; 
-
-    cout << "Top element is " << peek(root) << endl; 
-
-    return 0; 
-} 

Exercise_2.java

@@ -1,52 +0,0 @@
-public class StackAsLinkedList { 
-
-    StackNode root; 
-
-    static class StackNode { 
-        int data; 
-        StackNode next; 
-
-        StackNode(int data) 
-        { 
-            //Constructor here 
-        } 
-    } 
-
-
-    public boolean isEmpty() 
-    { 
-        //Write your code here for the condition if stack is empty. 
-    } 
-
-    public void push(int data) 
-    { 
-        //Write code to push data to the stack. 
-    } 
-
-    public int pop() 
-    { 	
-	//If Stack Empty Return 0 and print "Stack Underflow"
-        //Write code to pop the topmost element of stack.
-	//Also return the popped element 
-    } 
-
-    public int peek() 
-    { 
-        //Write code to just return the topmost element without removing it.
-    } 
-
-	//Driver code
-    public static void main(String[] args) 
-    { 
-
-        StackAsLinkedList sll = new StackAsLinkedList(); 
-
-        sll.push(10); 
-        sll.push(20); 
-        sll.push(30); 
-
-        System.out.println(sll.pop() + " popped from stack"); 
-
-        System.out.println("Top element is " + sll.peek()); 
-    } 
-} 

Exercise_2.js

@@ -1,36 +0,0 @@
-class StackAsLinkedList {
-​
-    static stackNode = class {
-​
-        constructor(d) {
-            //Constructor here
-            this.data = d;
-            this.next = null;
-        }
-    }
-​
-    function isEmpty() {
-        //Write your code here for the condition if stack is empty.
-    }
-​
-    function push(data) {
-       //Write code to push data to the stack.
-    }
-​
-    function pop() {
-       //If Stack Empty Return 0 and print "Stack Underflow"
-       //Write code to pop the topmost element of stack.
-       //Also return the popped element
-    }
-​
-    function peek() {
-       //Write code to just return the topmost element without removing it.
-    }
-}
-//Driver code
-const sll = new StackAsLinkedList();
-sll.push(10);
-sll.push(20);
-sll.push(30);
-console.log(sll.pop() + " popped from stack");
-console.log("Top element is " + sll.peek());

Exercise_2.py

@@ -1,15 +1,23 @@
-
+/time 0(1)
+/space 0(n)
 class Node:
     def __init__(self, data):
        self.data = data
        self.next = None
 
 class Stack:
     def __init__(self):
-
+        self.top = None
     def push(self, data):
-
+        new_node = Node(data)
+        new_node.next = self.top
+        self.top = new_node
     def pop(self):
+        if self.top is None:
+            return None
+        popped_value = self.top.data
+        self.top = self.top.next
+        return popped_val
 
 a_stack = Stack()
 while True: