Go Selection Sort

selection_sort.go

package main

import (
	"log"
	"math"
)

func main() {
	array := []int{}
	selectionSort(&array)
	assert([]int{}, array)

	array = []int{1}
	selectionSort(&array)
	assert([]int{1}, array)

	array = []int{1, 2}
	selectionSort(&array)
	assert([]int{1, 2}, array)

	array = []int{3, 1, 2}
	selectionSort(&array)
	assert([]int{1, 2, 3}, array)

	array = []int{3, 2, 1, 4}
	selectionSort(&array)
	assert([]int{1, 2, 3, 4}, array)

}

func selectionSort(arr *[]int) {
	if len(*arr) <= 1 {
		return
	}

	for i := range *arr {
		min := math.MaxInt32
		minIndex := 0
		for j, v := range (*arr)[i:] {
			if v <= min {
				min = v
				minIndex = i + j
			}
		}
		(*arr)[minIndex] = (*arr)[i]
		(*arr)[i] = min
	}

	return
}

func assert(expected, actual []int) {
	if len(expected) != len(actual) {
		log.Panicf("%s != %s", expected, actual)
	}
	for x := range expected {
		if expected[x] != actual[x] {
			log.Panicf("%s != %s", expected, actual)
		}
	}
}