ধারার যোগফল-C

#include <stdio.h>

const int p = 10007;

int main()

{

long long a, ans = 0;

long long n; scanf("%lld %lld", &a, &n);

a %= p;

int cum[p]; cum[0] = 0;

int i = 1, rem = 1, j;

if(n >= p) j = p - 1;

else j = n;

if(a!=0)

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

{

rem = (rem * a) % p;

ans = (ans + rem) % p;

cum[i] = ans;

}

long long fac = n / (p - 1);

if(fac!=0)

{

ans = (ans * (fac % p)) % p;

ans = (ans + cum[n % (p - 1)]) % p;

}

printf("%lld\n", ans);

return 0;

}