/*

 

 

P4Math functions for use in encryption ect...

 

by P4ll4t0n

 

*/

 

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

// BEGIN P4MATH.h

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

 

#define P4MAX( a, b ) ( a > b ? a : b )

#define P4MIN( a, b ) ( a < b ? a : b )

#define P4ABS( a ) ( a < 0 ? -1 * a : a )

#define P4FLOOR( a ) ( (int)( a - 0.5) )

#define P4CEIL( a ) ( (int)( a + 0.5 ) )

 

//Gets the Greatest common divisor of a and b

int P4Gcf( long int a, long int b );

 

//Gets the factorial of a number

long int P4Factorial( long int a );

 

//Simple does a exponents only does whole number exponents

long int P4Pow( int n, int e );

 

//Aprox's the sqrt of a number, the > iters is the more acurate the sqrt is

float P4AproxSqrt( float num, int iters );

 

//------END P4Math.h

 

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

// Start P4Math.c

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

#include "./P4Math.h"

int P4Gcf( long int a, long int b )

{

    int max = P4MAX( a, b );

    int min = P4MIN( a, b );

    int remain;

   

    while( min != 0 )

    {

           remain = max % min;

           

           max = min;

           min = remain;

    }

   

    return max;

}

 

long int P4Factorial( long int a )

{

     if( a == 1 || a == -1 )

         return 1;

     

     if( a < 0 )

         return a * P4Factorial( a + 1 );

     

     return a * P4Factorial( a - 1 );

}

 

long int P4Pow( int n, int e )

{

     if( e <= 0 )

         return 1;

         

     if( e == 1 )

         return n;

         

     return n * P4Pow( n, e - 1 );

}

 

float P4AproxSqrt( float num, int iters )

{

      if( num == 0 || num < 0 )

          return 0;

         

      float sqrt, q = num / 2;

     

      for( int i = 0; i < iters; i++ )

      {

           sqrt = ( q + num / q ) / 2;

           

           q = sqrt;

      }

     

      return sqrt;

}