Solution: count characters - sort by frequency

---

examples/count-characters-by-frequency/count_characters_by_frequency.go

package main

import (
    "fmt"
    "sort"
)

func main() {
    text := "This is a very long text. OK, maybe it is not that long after all."
    counter := make(map[string]int)
    for _, c := range text {
        //fmt.Printf("%v", string(c))
        if string(c) != " " {
            counter[string(c)]++
        }
    }

    fmt.Println(text)
    chars := make([]string, 0, len(counter))
    for chr := range counter {
        chars = append(chars, chr)
    }

    sort.Slice(chars, func(i, j int) bool {
        return counter[chars[i]] > counter[chars[j]]
    })
    for _, chr := range chars {
        fmt.Printf("%v: %v\n", chr, counter[chr])
    }

}