Add day 38

Author: MadhavBahl

README.md

@@ -65,6 +65,7 @@ Motivate yourself to code daily till 60 days, and see the magic! Coding will bec
 | [Day 35](./day35) | [Quick Sort](./day35) | [http://codetoexpress.tech/dc/day35/](http://codetoexpress.tech/dc/day35/) | **Intermediate** |
 | [Day 36](./day36) | [Radix Sort](./day36) | [http://codetoexpress.tech/dc/day36/](http://codetoexpress.tech/dc/day36/) | **Intermediate** |
 | [Day 37](./day37) | [Radix Sort](./day37) | [http://codetoexpress.tech/dc/day37/](http://codetoexpress.tech/dc/day37/) | **Misc** |
+| [Day 38](./day38) | [Implement Stack Data Structure](./day38) | [http://codetoexpress.tech/dc/day38/](http://codetoexpress.tech/dc/day38/) | **Beginner** |
 
 ## [More Problems](./BONUS/README.md)
 

day37/ques.png

@@ -0,0 +1,58 @@
+/**
+ * Implemntation of Stack Data  Structure in JavaScript
+ * @author MadhavBahlMD
+ * @date 11/02/2019
+ * Method 1 - Using JavaScript's push and pop methods
+ */
+
+class Stack {
+    // constructor to initialize the stack and it's capacity
+    constructor (limit) {
+        this.myStack = [];
+        this.top = limit;
+    }
+
+    // isEmpty method to check whether the stack is empty
+    isEmpty () {
+        if (this.myStack.length === 0)  return true;
+        else return false;
+    }
+
+    // isFull method to check whether the stack is full
+    isFull () {
+        if (this.myStack.length === this.top)  return true;
+        else return false;
+    }
+
+    // push method to add a record to the stack
+    push (record) {
+        if (!this.isFull()) {
+            console.log (`Pushing ${record} to the stack!`);
+            this.myStack.push (record);
+        } else {
+            console.log ('Sorry! The Stack is full!');
+        }
+    }
+
+    // pop method to remove an element from the stack
+    pop () {
+        if (!this.isEmpty()) {
+            console.log (`Popped element is: ${this.myStack[this.myStack.length-1]}`);
+            return this.myStack.pop ();
+        } else {
+            console.log ('Sorry! The Stack is empty');
+        }
+    }
+
+    // peek method to view the top element
+    peek () {
+        console.log (`Current element is: ${this.myStack[this.myStack.length - 1]}`);
+    }
+}
+
+const stk = new Stack (10);
+stk.pop ();
+stk.push (1);
+stk.push (2);
+stk.pop ();
+stk.peek ();

day38/Daily Codes.png

@@ -0,0 +1,68 @@
+/**
+ * Implemntation of Stack Data  Structure in JavaScript
+ * @author MadhavBahlMD
+ * @date 11/02/2019
+ * Method 2 - Stack implementation from scratch (without push() and pop() methods)
+ */
+
+class Stack {
+    // Constructor function to initialize the stack
+    constructor (capacity) {
+        this.myStack = [];
+        this.cap = capacity;
+        this.first = 0;
+        this.last = 0;
+        this.size = -1;
+    }
+
+    // isEmpty() method to check whether the stack is empty
+    isEmpty () {
+        if (this.size === -1) return true;
+        return false;
+    }
+
+    //isFull() method to check whether the stack is full
+    isFull () {
+        if (this.size === this.cap -1) return true;
+        return false;
+    }
+
+    // push() method to add an element to the stack
+    push (element) {
+        if (this.isFull()) {
+            console.log ('OVERFLOW!');
+            return 0;
+        }
+        console.log (`Pushing ${element} to the stack!`);
+        this.size++;
+        this.myStack[this.size] = element;
+        return 1;
+    }
+
+    // pop() method to remove topmost element
+    pop () {
+        if (this.isEmpty()) {
+            console.log ('UNDERFLOW!');
+            return 0;
+        }
+        console.log (`Popped element is: ${this.myStack[this.size]}`);
+        this.size--;
+        return 1;
+    }
+
+    // peek() method to view the toopmost element
+    peek () {
+        if (this.isEmpty()) {
+            console.log ('Stack is empty!');
+            return 0;
+        }
+        console.log (`Current Element is: ${this.myStack[this.size]}`);
+    }
+}
+
+const stk = new Stack (10);
+stk.pop ();
+stk.push (1);
+stk.push (2);
+stk.pop ();
+stk.peek ();

day38/JavaScript/stack1.js

@@ -0,0 +1,118 @@
+![cover](./cover.png)
+
+# Day 38 - Implementation of Stack Data Structure
+
+## What all did we see till now?
+
+Now that we are proceeding towards the phase 2 of Daily Codes initiative, here are the things that we focused on phase 1,
+
+- Basic questions
+- String Manipulation programs
+- Recursion
+- Array based programs
+- Time and space complexity in various programs
+- Searching algorithms
+- Sorting algorithms
+- Applications based on searching and sorting algorithms
+
+### Help us improve
+
+It's been a long journey, and I hope the people who are following this initiative daily are getting benefitted.
+Moreover, we would love to have your valuable feedback, and suggestions
+
+Just comment on issue [#244](https://github.com/CodeToExpress/dailycodebase/issues/244) - https://github.com/CodeToExpress/dailycodebase/issues/244 - whatever you would like us to know
+
+**Thanks for being a part, we love you all. Let's make this world a better place through code**
+
+## Today's question - Implement a Stack
+
+Stack is a linear data structure which follows a particular order in which the operations are performed. The order may be LIFO(Last In First Out) or FILO(First In Last Out)
+
+There are many real-life examples of a stack, like a stack of books, where you can add another book at top and remove the book at the top. Another example can be a stack of plates kept one over the other in the kitchen, one can remove the plate kept at top and remove the element kept at the top.
+
+A stack has various methods -
+
+1. `isEmpty()` - **To check whether the stack is empty**
+2. `isFull()` - **To check whether the stack is full**
+3. `push()` - **To add a new element to the stack**
+4. `pop()` - **To remove the topmost element from the stack**
+5. `peek()` - **To view the topmost element in the stack**
+
+Try to implement a stack 😁
+
+## Solution
+
+## JavaScript Implementation
+
+### [Solution 1](./JavaScript/stack1.js)
+
+Implementation by using JS's array push and pop methods
+
+```js
+/**
+ * Implemntation of Stack Data  Structure in JavaScript
+ * @author MadhavBahlMD
+ * @date 11/02/2019
+ * Method 1 - Using JavaScript's push and pop methods
+ */
+
+class Stack {
+    // constructor to initialize the stack and it's capacity
+    constructor (limit) {
+        this.myStack = [];
+        this.top = limit;
+    }
+
+    // isEmpty method to check whether the stack is empty
+    isEmpty () {
+        if (this.myStack.length === 0)  return true;
+        else return false;
+    }
+
+    // isFull method to check whether the stack is full
+    isFull () {
+        if (this.myStack.length === this.top)  return true;
+        else return false;
+    }
+
+    // push method to add a record to the stack
+    push (record) {
+        if (!this.isFull()) {
+            console.log (`Pushing ${record} to the stack!`);
+            this.myStack.push (record);
+        } else {
+            console.log ('Sorry! The Stack is full!');
+        }
+    }
+
+    // pop method to remove an element from the stack
+    pop () {
+        if (!this.isEmpty()) {
+            console.log (`Popped element is: ${this.myStack[this.myStack.length-1]}`);
+            return this.myStack.pop ();
+        } else {
+            console.log ('Sorry! The Stack is empty');
+        }
+    }
+
+    // peek method to view the top element
+    peek () {
+        console.log (`Current element is: ${this.myStack[this.myStack.length - 1]}`);
+    }
+}
+
+const stk = new Stack (10);
+stk.pop ();
+stk.push (1);
+stk.push (2);
+stk.pop ();
+stk.peek ();
+```
+
+### [Solution 2](./JavaScript/stack2.js)
+
+Implementation without using JS's array push and pop methods
+
+```js
+// to be added
+```