stackarray.java

many simple java programs like classic algorithems to do search and few data structure implimentatio

import java.io.*;
import java.util.Scanner;

class stack
{
  int a[],top,count;

  public stack(int x)
  {
   a=new int[x];
   top=-1;
   count=0;
  }
  
  public void push(int x)
  {
   if(top>a.length)
     System.out.println("Stack overflow!");
   else
   {
     top++;
     a[top]=x;
     count++;
   }
  }

  public void pop()
  {    
    if(top>-1)
    {
     System.out.println("Element "+a[top]+" deleted");
     top--;
     count--;
    }
    else
      System.out.println("Stack under flow!");
  }

  public void status()
  {
    System.out.println("Stack contains "+count+" elements\nThey are:");
    for(int i=top;i>-1;i--)
      System.out.println(a[i]);
  }

}

public class stackarray
{
  public static void main(String args[])
  {
    int ch;
    Scanner s=new Scanner(System.in);
    System.out.print("Enter size of stack:");
    stack st=new stack(s.nextInt());
    do
    {
      System.out.println("Choose and option: \n1. PUSH\n2. POP\n3. STATUS\n4. EXIT");
      System.out.print("\n\nEnter ur choice:");
      ch=s.nextInt();
      switch(ch)
      {
       case 1:
         System.out.print("Enter the value to be entered :");
         st.push(s.nextInt());
         break;
       case 2:
         st.pop();
         break;
       case 3:
         st.status();
         break;
       case 4:
         break;
       default:
         System.out.println("Invalid choice!");  
      }
    }
    while(ch!=4);
  }
}