Sha256: a6bf98995b07632fe52eef9acbc368d1ada8c73328c2873a1a778fef113d8834
Contents?: true
Size: 1.41 KB
Versions: 122
Compression:
Stored size: 1.41 KB
Contents
package spiralmatrix
import (
"fmt"
)
type coordinate struct {
x int
y int
}
func (co coordinate) withinGrid(size int) bool {
return co.x >= 0 && co.x < size && co.y >= 0 && co.y < size
}
type direction int
const (
up direction = iota
right
down
left
)
func (d direction) move(co coordinate) coordinate {
switch d {
case up:
return coordinate{
x: co.x - 1,
y: co.y,
}
case right:
return coordinate{
x: co.x,
y: co.y + 1,
}
case down:
return coordinate{
x: co.x + 1,
y: co.y,
}
case left:
return coordinate{
x: co.x,
y: co.y - 1,
}
default:
panic(fmt.Sprintf("unexpected direction to move: %v", d))
}
}
func (d direction) turnRight() direction {
switch d {
case up:
return right
case right:
return down
case down:
return left
case left:
return up
default:
panic(fmt.Sprintf("unexpected direction to turn right: %v", d))
}
}
// SpiralMatrix is an implementation of the spiral matrix exercise.
func SpiralMatrix(size int) [][]int {
matrix := make([][]int, size)
for i := range matrix {
matrix[i] = make([]int, size)
}
co := coordinate{
x: 0,
y: 0,
}
dir := right
count := size * size
for i := 0; i < count; i++ {
matrix[co.x][co.y] = i + 1
maybeNext := dir.move(co)
if maybeNext.withinGrid(size) && matrix[maybeNext.x][maybeNext.y] == 0 {
co = maybeNext
} else {
dir = dir.turnRight()
co = dir.move(co)
}
}
return matrix
}
Version data entries
122 entries across 122 versions & 1 rubygems