/* 

Project 3
Exercise 3:- which is Exercise 4, pg 106

--> with text only user interface

The problem :-

1) Pi/4 = 1 - 1/3 + 1/5 - 1/7 .....
2) User inputs how many iterations they want
3) Pi = 3.14 roughly

Pseudocode :-

1) read no times want to iterate into numiter
2) i = 1;
3) x = 1;
4) while (i <= numiter) {
   
    if(i % 2 == 0){
    valuesofar = valuesofar  - (1 / x);
    }
    else {
     valuesofar = valuesofar + (1 / x);  
   }
   
   x = x + 2;
   
}
   display valuesofar;

*/

import TerminalIO.*;

public class Liebniz {
   
   KeyboardReader reader = new KeyboardReader();
   ScreenWriter writer = new ScreenWriter();
   
   int i;
   int x;
   int numiter;
   double valuesofar;
     
//================================================================
   public void run() {
      
   
   numiter = reader.readInt("Enter number iterations for Pi value: ");
   
      
   i = 1;
   x = 1;
   valuesofar = 0;
   
   while (i <= numiter) {
   
    if(i % 2 == 0){
    valuesofar = valuesofar  - (1 / x);
    }
    else {
     valuesofar = valuesofar + (1 / x);  
   }
   
   x = x + 2;
   
  }
   
   writer.println("The value so far is: " + valuesofar);
      
      
   }

//=================================================================
   public static void main(String [] args) {
      Liebniz tpo = new Liebniz();
      tpo.run();   
   }
}