Stack added.

Author: phyex0

src/com/company/DataStructures/Stack.java

@@ -0,0 +1,68 @@
+package com.company.DataStructures;
+
+/*
+* Stack:
+* Inserting = o(1)
+* Removing = o(1)
+* Peeking = o(1)
+* Checking capacity = o(1)
+*
+* In stack, first in, last out. Due to structure, you cannot take the item which is bottom first.
+*
+* */
+
+public class Stack {
+ private int[] myArray;
+ private int size;
+ private int index =-1;
+
+ //Constructor of the stack.
+ public Stack(int size) {
+ this.size = size;
+ myArray = new int[size];
+ }
+
+ // Checking the stack about being empty.
+ public boolean isEmpty(){
+ if(index ==-1){
+ System.out.println("Stack is empty!");
+ return true;
+ }
+ return false;
+
+ }
+
+ //Checking the stack about being full.
+ public boolean isFull(){
+ if(index+1 ==size){
+ System.out.println("Stack is full!");
+ return true;
+ }
+ return false;
+ }
+
+ //Inserting data.
+ public void push(int val){
+ if(!isFull())
+ myArray[++index]=val;
+ }
+
+ //Removing data.
+ public int pop(){
+ if(!isEmpty())
+ return myArray[index--];
+ return -1;
+ }
+
+ //Returning last item of the stack but it won't be removed.
+ public int peek(){
+ if(!isEmpty())
+ return myArray[index];
+ return -1;
+ }
+
+ //returns the current size of the stack.
+ public int getSize(){
+ return index;
+ }
+}

src/com/company/Main.java

@@ -1,18 +1,22 @@
 package com.company;
 
-import com.company.Algorithms.BubbleSort;
-import com.company.Algorithms.LinearSearch;
-import com.company.DataStructures.LinkedList;
+import com.company.DataStructures.Stack;
 
 public class Main {
 
  public static void main(String[] args) {
 // write your code here
- int[] arr = new int[]{10,9,9,8,7,5,4,3,2,1};
- BubbleSort.bubbleSort(arr);
+ Stack myStack = new Stack(5);
 
- System.out.println(LinearSearch.linearSearch(arr,10));
+ for(int i=0;i<5;i++){
+ myStack.push(i*10);
+ System.out.println(myStack.peek());
+ }
+ myStack.push(20);
 
+ for(int i=0;i<5;i++)
+ System.out.println(myStack.pop());
+ System.out.println(myStack.pop());
 
 
  }