package main

import (
    "fmt"
    "sort"
)

type RuneSlice []rune

func (p RuneSlice) Len() int           { return len(p) }
func (p RuneSlice) Less(i, j int) bool { return p[i] < p[j] }
func (p RuneSlice) Swap(i, j int)      { p[i], p[j] = p[j], p[i] }

func isPumpung(str1, str2 string) bool {
    // if lengths are not equal - false
    if len(str1) == len(str2) {
        return false
    }

    // sort both strings/runes
    var rune1 RuneSlice = []rune(str1)
    var rune2 RuneSlice = []rune(str2)

    sort.Sort(rune1)
    sort.Sort(rune2)

    //fmt.Println(string(rune1[:]))
    //fmt.Println(string(rune2[:]))

    // compare rune1 and rune 2 by indexes
    for i := 0; i < len(rune1); i++ {
        if rune1[i] != rune2[i] {
            return false
        }
    }

    return true
}

func main() {
    fmt.Println("18,19,20,21 and 21,20,18,20,19,18,20 is permutation of each other : ", isPumpung("18,19,20,21", "21,20,18,20,19,18,20"))
    fmt.Println("18,19,20,21 and 21,20,18,20,18,20 is permutation of each other : ", isPumpung("18,19,20,21", "21,20,18,20,18,20"))

}