Zenit 3 987654327 2 5 vypocita zvysok velkeho exponencialneho cisla. - http://stackoverflow.com/questions/5989429/pow-and-mod-function-optimization

gistfile1.cpp

uint64_t expmod(uint64_t base, uint64_t exp, uint64_t mod ){
  if (exp == 0) return 1;
  return (exp % 2 == 0) ? ( ((uint64_t) pow( expmod( base, (exp / 2), mod), 2) ) % mod ) : ((base * expmod( base, (exp - 1), mod)) % mod);
}