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| -rw-r--r-- | julia/062-cubic_permutations.jl | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/julia/062-cubic_permutations.jl b/julia/062-cubic_permutations.jl new file mode 100644 index 0000000..08c07fc --- /dev/null +++ b/julia/062-cubic_permutations.jl @@ -0,0 +1,32 @@ +### +# Cubic permutations +# Problem 62 +# +# The cube, 41063625 (345^3), can be permuted to produce two other cubes: 56623104 (384^3) +# and 66430125 (405^3). In fact, 41063625 is the smallest cube which has exactly three +# permutations of its digits which are also cube. +# Find the smallest cube for which exactly five permutations of its digits are cube. +### + + +using Base.Iterators + +cache = Dict() + +const PERMUTATIONS_COUNT = 5 + +for n in countfrom(2) + cube = n ^ 3 + key = sort(collect(string(cube))) + if !haskey(cache, key) + cache[key] = [cube] + else + push!(cache[key], cube) + end + for v in values(cache) + if length(v) == PERMUTATIONS_COUNT + println(minimum(v)) + exit(0) + end + end +end |