Given the size, return a square matrix of numbers in spiral order.
The matrix should be filled with natural numbers, starting from 1 in the top-left corner, increasing in an inward, clockwise spiral order, like these examples:
1 2 3
8 9 4
7 6 5
1 2 3 4
12 13 14 5
11 16 15 6
10 9 8 7
Reddit r/dailyprogrammer challenge #320 [Easy] Spiral Ascension. https://www.reddit.com/r/dailyprogrammer/comments/6i60lr/20170619_challenge_320_easy_spiral_ascension/
This exercise has been tested on Julia versions >=1.0.
It's possible to submit an incomplete solution so you can see how others have completed the exercise.
In [ ]:
# submit
function spiral_matrix(n::Int)
end
In [ ]:
using Test
# include("spiral-matrix.jl")
@testset "Different valid values" begin
@testset "Empty spiral" begin
@test spiral_matrix(0) == Matrix{Int}(undef,0,0)
end
@testset "Trivial spiral" begin
@test spiral_matrix(1) == reshape([1],(1,1))
end
@testset "Spiral of size 2" begin
@test spiral_matrix(2) == [1 2; 4 3]
end
@testset "Spiral of size 3" begin
@test spiral_matrix(3) == [1 2 3; 8 9 4; 7 6 5]
end
@testset "Spiral of size 4" begin
@test spiral_matrix(4) == [1 2 3 4; 12 13 14 5; 11 16 15 6; 10 9 8 7]
end
@testset "Spiral of size 5" begin
@test spiral_matrix(5) == [1 2 3 4 5; 16 17 18 19 6; 15 24 25 20 7; 14 23 22 21 8; 13 12 11 10 9]
end
end
To submit your exercise, you need to save your solution in a file called spiral-matrix.jl
before using the CLI.
You can either create it manually or use the following functions, which will automatically write every notebook cell that starts with # submit
to the file spiral-matrix.jl
.
In [ ]:
# using Pkg; Pkg.add("Exercism")
# using Exercism
# Exercism.create_submission("spiral-matrix")