#include<iostream.h>


#include<limits.h>


#include<iomanip.h>





void toggleflag(bool &x);





//This program is based on the following algorithm to find PI:


//Pi = 4A


//A= 1 - 1/3 + 1/5 - 1/7 + 1/9....





int main()


{


	cout << "Snerlin's Pi calculator" << endl << "t\t\by Stephen Lindberg(Snerlin)";


   cout << "Press enter to start." <<endl;


   cin.get();        


   double pi=1.000000000000000;


   double add=3;


   bool flag=false;


   int counter=0;


   while(add<INT_MAX-3)


   {


      if(counter%1000000==0)


      {


   		cout << setprecision(15);


   		cout << 4*pi << endl;


      }


   	if(!flag)


      {


      	pi-=1/add;


      }


      if(flag)


      {


      	pi+=1/add;


      }


      toggleflag(flag);


      add+=2;


      ++counter;


   }


   cout << "\n\nerror: You know how computers can only\n store a number up to a certain maximum number?\nThe adder in the algorithm reached the limit and went \n.all the way down to the lowest possible negative number.\n";


   cout << "goodbye and have a nice day! ;P";


   cin.get();


   return 0;


}





void toggleflag(bool &x)


{


	int a=0;


   if(!x)


   {


   	x=true;


      a=1;


   }


   if((x)&&(a==0))


   {


   	x=false;


   }


}

Edited by the Author.

void toggleflag(bool &x)


{


	int a=0;


   if(!x)


   {


   	x=true;


      a=1;


   }


   if((x)&&(a==0))


   {


   	x=false;


   }


}

Edited by the Author.

precision=input("Select Precision : ")


max,i,pi,result=pow(10,(precision)),1,0,1


while result>0:


	result=max/i


	if ((i-1)/2)&1:


		pi-=result


	else:


		pi+=result


	i=i+2


	if (i==10000003):


		print "press ^C if it last too long"


print "pi value : ",(4*pi)

Edited more than twice by the Author.

Edited by the Drunk Author.

Edited by the Author.

// --------------------------------------------------- //


// ---           PI Calculator by Kramy            --- //


// --------------------------------------------------- //


// --- #Pi Calculator Requires Slint v1.3 or newer --- //


// --------------------------------------------------- //


// PiCalc uses the following Formula to find PI:       //


// // 1 -1/3 +1/5 -1/7 +1/9...                         //


// --------------------------------------------------- //


// When making a new Pi Calculator, specify the number //


// of digits to store.                                 //


// --------------------------------------------------- //


// To get any level of accuracy you must call          //


// myPiCalculate.CalculatePI atleast Digits(cubed)  //


// --------------------------------------------------- //


// The n is used to update the percentage of the       //


// calculations completed.                             //


// --------------------------------------------------- //





// Make window for Result


myWindow = New Window(320,240,0,0,0xFFFFFF,8,"Kramy's Pi Calculator");


myWindow.SetAutoRefresh(FALSE);


myWindow.CENTER();


// Edit for showing result


myEdit = New Edit(myWindow,"",4,4,212,232,Edit.VSCROLL,Edit.MULTILINE);





// Make Pi Calculator (Digits)


myPiCalculator = New PiCalc(16);


Var Steps = 0;


Var PrevSteps = 0;





While(1)


{


// Raise Steps


Steps++;


// Calculate


myPiCalculator.CalculatePi();


If(Steps >= PrevSteps + 100)


 {


 // Update Steps


 PrevSteps += 100;


 


 // Get Result


 Var myResult = myPiCalculator.Result(Steps);


 // Add Decimal


 myResult = myResult.SubString(0,1)+"."+myResult.SubString(1,myResult.Length()-1);


 // Set Editbox to result for easier reading.


 myEdit.SetText(myResult);


 


 // Refresh Window


 myWindow.Refresh();


 }


}








Function PiCalc(pDigits)


{


// Precision


This.Digits = pDigits;


This.Divisor = 1;


This.isNeg = FALSE;





// Slint for End Result*4


This.myPI = New Slint("1");





// Slints for End Result


This.myCalc2 = New Slint("1");


For(PiCalcLoop = This.Digits;PiCalcLoop > 0;PiCalcLoop--) This.myCalc2.Mul("10");





// Slint for Calculations


This.myCalc = New Slint(myCalc2.Get());





// String for resetting


This.myPrecisionStr = myCalc2.Get();





// Calculate


This.CalculatePi = PiCalc_Calculate;


This.Result = PiCalc_Result;


}





Function PiCalc_Calculate()


{


// Increment Divisor


Divisor += 2;


// Switch from Positive to Negative


If(IsNeg) IsNeg = FALSE;


Else IsNeg = TRUE;


 


// -1/3 +1/5 -1/7 +1/9...


myCalc.Set(myPrecisionStr);


myCalc.Div(Divisor);


 


If(IsNeg) myCalc2.Sub(myCalc.Get());


Else myCalc2.ADD(myCalc.Get());


}





Function PiCalc_Result(pSteps)


{


myWindow.SetText("Digits: "+Digits+" Calculations: "+pSteps);


// Make Final Calculation


myPI.Set(myCalc2.Get());


myPi.Mul("4");


// Return to wherever


Return myPi.Get();


}