https://projecteuler.net/problem=16

euler16.go

package main

import (
	"fmt"
	"math/big" // Seems like a copout
)

func main() {
	s := big.NewInt(1)
	s.Lsh(s, 1000)
	base := big.NewInt(10)
	mod := big.NewInt(1)
	sum := 0
	zero := big.NewInt(0)
	for s.Cmp(zero) != 0 {
		s.DivMod(s, base, mod)
		sum += int(mod.Int64())
	}
	fmt.Println(sum)
}