[Golang] Digit fifth powers - Problem 30 - Project Euler

Problem: [1]

Surprisingly there are only three numbers that can be written as the sum of fourth powers of their digits:

1634 = 1^4 + 6^4 + 3^4 + 4^4

8208 = 8^4 + 2^4 + 0^4 + 8^4

9474 = 9^4 + 4^4 + 7^4 + 4^4

As 1 = 1^4 is not a sum it is not included.

The sum of these numbers is 1634 + 8208 + 9474 = 19316.

Find the sum of all the numbers that can be written as the sum of fifth powers of their digits.

Solution:

443839

Run Code on Go Playground

package main

import (
      "fmt"
      "strconv"
)

func IsFifthPowerEqual(n int) bool {
      s := strconv.Itoa(n)
      sum := 0
      for _, digit := range s {
              d, err := strconv.Atoi(string(digit))
              if err != nil {
                      panic(err)
              }
              sum += d * d * d * d * d
      }
      if sum == n {
              return true
      }
      return false
}

func main() {
      d95 := 9 * 9 * 9 * 9 * 9
      fmt.Println("9^5 =", d95)
      fmt.Println("max possible: 6 * 9^5 =", 6*d95)
      sum := 0
      for i := 2; i < 6*d95; i++ {
              if IsFifthPowerEqual(i) {
                      fmt.Println(i)
                      sum += i
              }
      }
      fmt.Println("Sum:", sum)
}

Result:

9^5 = 59049
max possible: 6 * 9^5 = 354294
4150
4151
54748
92727
93084
194979
Sum: 443839

Test on:

Ubuntu Linux 17.10, Go 1.10.2
Go Playground

References:

[1]	Digit fifth powers - Problem 30 - Project Euler