Create Spiral with Arrays in Golang

Readme_spiral.md

Task taked from codewars.com: Make a spiral using Golang

Our task, is to create a NxN spiral with a given size.

For example, spiral with size 5 should look like this:

00000 ....0 000.0 0...0 00000

and with the size 10:

0000000000 .........0 00000000.0 0......0.0 0.0000.0.0 0.0..0.0.0 0.0....0.0 0.000000.0 0........0 0000000000

Return value should contain array of arrays, of 0 and 1, for example for given size 5 result should be:

[[1,1,1,1,1],[0,0,0,0,1],[1,1,1,0,1],[1,0,0,0,1],[1,1,1,1,1]]

Because of the edge-cases for tiny spirals, the size will be at least 5.

General rule-of-a-thumb is, that the snake made with '1' cannot touch to itself.

spiral.go

package spiral

func Spiralize(n int) [][]int {
	return [][]int{{1, 1}, {0, 1}}
}

spiral_test.go

package spiral

import (
	"reflect"
	"testing"
)

func TestSpiralize(t *testing.T) {
	cases := []struct {
		in   int
		want [][]int
	}{
		{1, [][]int{{1}}},
		{2, [][]int{
			{1, 1},
			{0, 1}}},
		{3, [][]int{
			{1, 1, 1},
			{0, 0, 1},
			{1, 1, 1}}},
		{5, [][]int{
			{1, 1, 1, 1, 1},
			{0, 0, 0, 0, 1},
			{1, 1, 1, 0, 1},
			{1, 0, 0, 0, 1},
			{1, 1, 1, 1, 1}}},
		{13, [][]int{
			{1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1},
			{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1},
			{1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1},
			{1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1},
			{1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1},
			{1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1},
			{1, 0, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 1},
			{1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1},
			{1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1},
			{1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1},
			{1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1},
			{1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1},
			{1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}}},
	}

	for _, tt := range cases {
		actual := Spiralize(tt.in)

		if !reflect.DeepEqual(actual, tt.want) {
			t.Errorf("Spiralize(%d): expected %v, actual %v", tt.in, tt.want, actual)
		}
	}

}