Mimic Python's collection.Counter in Go - attempt 2

counter.go

package counter

import (
	"fmt"
	"sort"
)

type kv struct {
	Key   int
	Value int
}

type Counter interface {
	Counts() map[int]int
	MostCommon(n int) map[int]int
}

type IntCounter []int

func (ic IntCounter) Counts() map[int]int {
	counts := make(map[int]int)
	for _, i := range ic {
		counts[i]++
	}
	return counts
}


func (ic IntCounter) MostCommon(n int) map[int]int {
	counts := ic.Counts()

	// A slice of (Key, Value) structs
	var ss []kv

	for k, v := range counts {
		ss = append(ss, kv{k, v})
	}

	// Greatest to smallest, by value
	// Sort the provided slice given the provided "less" function
	sort.Slice(ss, func(i, j int) bool { return ss[i].Value > ss[j].Value })
	result := make(map[int]int)
	for i:= 0; i < n; i++ {
		pair := ss[i]
		result[pair.Key] = pair.Value
	}
	return result
}

func main() {
	ic := IntCounter([]int{1, 1, 2, 3, 4, 4, 4, 5, 6, 7, 7, 7, 7})
	fmt.Println(ic.MostCommon(m, 3))
}