Counting sort implementation in Go

counting_sort.go

package main

import "fmt"

func countingSort(numbers []int, maxValue int) []int {

        // Allocate a numCounts slice with cap of the maxValue + 1                      
        // Make sure it's allocated (zero-filled) and not empty.                        
        numCounts := make([]int, maxValue+1)

        // For each number in numbers                                                   
        for _, num := range numbers {
                // numCounts index becomes the number, and the value                    
                // at each index becomes the time the number appears                    
                // So keeps increment when a number is found.                           
                numCounts[num] += 1
        }

        // Allocate the target slice                                                    
        // Make sure it's empty and not zero-filled.                                    
        sorted := []int{}

        // Loop over the number and count in numCounts                                  
        for num, count := range numCounts {
                        // count being the time a number can appear                             
                // i.e. if 2 appears 3 times, 2 will be appended 3 times                
                // before the above loop moves on to the next num, count                
                for time := 0; time < count; time++ {
                        sorted = append(sorted, num)
                }
        }

        return sorted
}

func main() {
        nums := []int{1, 2, 10, 10, 4, 6, 10, 2, 2, 54}
        sorted = countingSort(nums, 54)
        fmt.Println(sorted)
}