Gfrktyl

I'm new to programming and i cant seem to find the mistake that makes my program find 6 more primes than it should.The correct answer for the given range is 904533.

In addition,suggested run time is around 5 seconds while mine is around 8.

Hope someone could help me, thank you in advance.

#define MINNUM 3990000000

#define MAXNUM 4010000000

#include <stdio.h>



int main()

{               

unsigned int  r,j,i,checker,k,primecount=0,d,d_save;  //

unsigned int a;

unsigned long long res=1;



printf("Checking range [3990000000,4010000000] for primes...");



    for (k=MINNUM+1;k<=MAXNUM-2;k+=2)

{

    checker = 0;

if(k % 3 != 0)

{

 d = k - 1;         // Reset variables

 res = 1;

 r = 0;

//Create (2^r)*d= n-1



while(d%2==0){

                r++;

                d/=2;

            }

//printf("%u can be written as : (2^%d)*%llun",k-1,r,d);   



    d_save=d; //saves d for each j loop



do{



for(j=1;j<=3;j++)

{

    d=d_save;



    res=1;

if (j==1) a=2;

if (j==2) a=7;

if (j==3) a=61;



//Calculate a^d mod k

    while (d>0)                 

        { 

            // When y is odd 

            if (d & 1) 

                res = (res*a) % k; 



          // When y is even 

            d = d>>1;       //Same as y = y/2 

            a = (a*a) % k; 



        } 



//Miller Rabin's c

    if (res == 1 || res == k-1) { checker=1; continue;}



    while (r!=0 ) 

    { 



        res = (res * res) % k;                                       





        if (res == 1)     { checker=0;  break;}



        if (res == k-1)   {  checker=1; break;}



        r--;

    } 





}

}

while (checker==1);



//printf("check %u %dn",k,checker);

if (checker==1) primecount++;

}

}

printf("primes are %u",primecount);

}