Matrix Spiral

main.go

package main

import "fmt"

var Matrix = [][]int{
	{63, 22, 17, 39, 36},
	{53, 22, 31, 40, 36},
	{43, 81, 11, 41, 36},
	{13, 22, 87, 42, 38},
	{33, 22, 91, 47, 99},
}

type Direction int

const (
	start = Direction(0)
	left  = Direction(1)
	right = Direction(2)
	up    = Direction(3)
	down  = Direction(4)
)

func nextDirection(d Direction) Direction {
	switch d {
	case start:
		return down
	case down:
		return left
	case left:
		return up
	case up:
		return right
	case right:
		return down
	}
	return d
}

func main() {
	elCount := 25
	posX, posY := 2, 2

	stepNum := 0
	stepSize := 1
	direction := nextDirection(start)
	dch := 0

	fmt.Printf("%d ", Matrix[posY][posX])

	for i := 0; i < elCount-1; i++ {

		switch direction {
		default:
			panic("unknown direction")
		case up:
			posY -= 1
		case down:
			posY += 1
		case left:
			posX -= 1
		case right:
			posX += 1
		}

		fmt.Printf("%d ", Matrix[posY][posX])

		stepNum++
		if stepNum == stepSize {
			stepNum = 0
			direction = nextDirection(direction)
			dch++
			if dch == 2 {
				stepSize++
				dch = 0
			}
		}
	}
	fmt.Println("")

}