Project Euler #26 in Golang

euler_26.go

package main

import (
	"fmt"
	"math/big"
	"sort"
	"strings"
)

func findReciprocal(s string) string {
	length := len(s)

	if length == 1 {
		return "n/a"
	}

	for padding := 0; padding < 4; padding += 1 {
		for i := 1; i < (length-padding)/2; i += 1 {
			base := s[padding:length]
			candidate := s[padding : padding+i]
			x := strings.Replace(base, candidate, "", -1)
			xl := len(x)
			//fmt.Printf(". find %s in %s as %s\n", candidate, base, x)
			if strings.Count(base, candidate) > 1 && (
				xl == 0 || (xl < len(candidate) && strings.HasPrefix(candidate, x))) {
				return candidate
			}
		}
	}

	return "n/a"
}

func main() {
	keys := make([]int, 0)
	result := make(map[int][]int)
	for i := 2; i < 1000; i++ {
		s := big.NewRat(1, int64(i)).FloatString(4096)
		v := strings.Split(s[0:len(s)-1], ".")[1]
		r := findReciprocal(v)
		if r != "n/a" {
			rl := len(r)
			if _, ok := result[rl]; !ok {
				keys = append(keys, rl)
				result[rl] = []int{i}
			} else {
				result[rl] = append(result[rl], i)
			}
		}
	}

	sort.Ints(keys)
	for _, v := range keys {
		fmt.Printf("%2d -> %v\n", v, result[v])
	}
}