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ProvocaTeach's solution

to Anagram in the Julia Track

Published at Feb 24 2021 · 0 comments
Instructions
Test suite
Solution

An anagram is a rearrangement of letters to form a new word. Given a word and a list of candidates, select the sublist of anagrams of the given word.

Given "listen" and a list of candidates like "enlists" "google" "inlets" "banana" the program should return a list containing "inlets".

Source

Inspired by the Extreme Startup game https://github.com/rchatley/extreme_startup

Version compatibility

This exercise has been tested on Julia versions >=1.0.

Submitting Incomplete Solutions

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runtests.jl

using Test

include("anagram.jl")

@testset "no matches" begin
    @test detect_anagrams("diaper", ["hello", "world", "zombies", "pants"]) == []
end

@testset "detects simple anagram" begin
    @test detect_anagrams("ant", ["tan", "stand", "at"]) == ["tan"]
end

@testset "does not detect false positives" begin
    @test detect_anagrams("galea", ["eagle"]) == []
end

@testset "detects two anagrams" begin
    @test detect_anagrams("master", ["stream", "pigeon", "maters"]) == ["stream", "maters"]
end

@testset "does not detect anagram subsets" begin
    @test detect_anagrams("good", ["dog", "goody"]) == []
end

@testset "detects anagram" begin
    @test detect_anagrams("listen", ["enlists", "google", "inlets", "banana"]) == ["inlets"]
end

@testset "detects three anagrams" begin
    @test detect_anagrams("allergy", ["gallery", "ballerina", "regally", "clergy", "largely", "leading"]) == ["gallery", "regally", "largely"]
end

@testset "detects multiple anagrams with different case" begin
    @test detect_anagrams("nose", ["Eons", "ONES"]) == ["Eons", "ONES"]
end

@testset "does not detect identical words" begin
    @test detect_anagrams("corn", ["corn", "dark", "Corn", "rank", "CORN", "cron", "park"]) == ["cron"]
end

@testset "does not detect non-anagrams with identical checksum" begin
    @test detect_anagrams("mass", ["last"]) == []
end

@testset "detects anagrams case-insensitively" begin
    @test detect_anagrams("Orchestra", ["cashregister", "Carthorse", "radishes"]) == ["Carthorse"]
end

@testset "detects anagrams using case-insensitive subject" begin
    @test detect_anagrams("Orchestra", ["cashregister", "carthorse", "radishes"]) == ["carthorse"]
end

@testset "detects anagrams using case-insensitive possible matches" begin
    @test detect_anagrams("orchestra", ["cashregister", "Carthorse", "radishes"]) == ["Carthorse"]
end

@testset "does not detect an anagram if the original word is repeated" begin
    @test detect_anagrams("go", ["go Go GO"]) == []
end

@testset "does not detect a word as its own anagram" begin
    @test detect_anagrams("banana", ["Banana"]) == []
end

@testset "does not detect a anagram if the original word is repeated" begin
    @test detect_anagrams("go", ["go Go GO"]) == []
end

@testset "anagrams must use all letters exactly once" begin
    @test detect_anagrams("tapper", ["patter"]) == []
end

@testset "words are not anagrams of themselves (case-insensitive)" begin
    @test detect_anagrams("BANANA", ["BANANA", "Banana", "banana"]) == []
end

@testset "words other than themselves can be anagrams" begin
    @test detect_anagrams("LISTEN", ["Listen", "Silent", "LISTEN"]) == ["Silent"]
end

@testset "capital word is not own anagram" begin
    @test detect_anagrams("BANANA", ["Banana"]) == []
end
#=  Create a canonical representation of every word
    by alphabetizing and capitalizing. For example,
    `"abcbade"` becomes `['A' 'A' 'B' 'B' 'C' 'D' 'E']`.
=#
canonRep = sort∘collect∘uppercase

# `subject` is a string
# `candidates` is a list of strings
function detect_anagrams(subject, candidates)
    uSubject = uppercase(subject)
    cSubject = (sort∘collect)(uSubject) # we need the uppercase version later

    cCandidates = map(canonRep, candidates)

    indices = []
    for i in eachindex(cCandidates)
        # two conditions: 1) canonical representations match
        #                 2) they are not the same word :eyeroll
        if cSubject == cCandidates[i] && uSubject != uppercase(candidates[i])
            append!(indices, i)
        end
    end
    output = candidates[indices]
end

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ProvocaTeach's Reflection

Ugh, their definition of anagrams is annoying. I'm a mathematician; we have equivalence relations where everything is an anagram of itself, and 'a' =/= 'A'.