Family Day update

Task/Find-the-missing-permutation/Julia/find-the-missing-permutation-1.julia

@@ -1,8 +1,8 @@
-using Combinatorics
+using BenchmarkTools, Combinatorics
+
 function missingperm(arr::Vector)
-    allperms = permutations(arr[1])
+    allperms = String.(permutations(arr[1]))  # revised for type safety
     for perm in allperms
-        perm = convert(eltype(arr), perm)
         if perm ∉ arr return perm end
     end
 end

Task/Find-the-missing-permutation/Julia/find-the-missing-permutation-2.julia

@@ -10,8 +10,3 @@ function missingperm1(arr::Vector{<:AbstractString})
     end
     return missperm
 end
-
-using BenchmarkTools
-
-@btime missingperm(arr)
-@btime missingperm1(arr)

Task/Find-the-missing-permutation/Julia/find-the-missing-permutation-3.julia

@@ -0,0 +1,16 @@
+function missingperm2(arr::Vector)
+    len = length(arr[1])
+    xorval = zeros(UInt8, len)
+    for perm in [Vector{UInt8}(s) for s in arr], i in 1:len
+        xorval[i] ⊻= perm[i]
+    end
+    return String(xorval)
+end
+
+@show missingperm(arr)
+@show missingperm1(arr)
+@show missingperm2(arr)
+
+@btime missingperm(arr)
+@btime missingperm1(arr)
+@btime missingperm2(arr)