54 lines
1.4 KiB
Nim
54 lines
1.4 KiB
Nim
import strformat, strutils, threadpool
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const Numbers = [576460752303423487,
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576460752303423487,
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576460752303423487,
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112272537195293,
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115284584522153,
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115280098190773,
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115797840077099,
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112582718962171,
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299866111963290359]
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proc lowestFactor(n: int64): int64 =
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if n mod 2 == 0: return 2
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if n mod 3 == 0: return 3
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var p = 5
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var delta = 2
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while p * p < n:
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if n mod p == 0: return p
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inc p, delta
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delta = 6 - delta
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result = n
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proc factors(n, lowest: int64): seq[int64] =
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var n = n
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var lowest = lowest
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while true:
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result.add lowest
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n = n div lowest
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if n == 1: break
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lowest = lowestFactor(n)
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# Launch a thread for each number to process.
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var responses: array[Numbers.len, FlowVar[int64]]
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for i, n in Numbers:
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responses[i] = spawn lowestFactor(n)
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# Read the results and find the largest minimum prime factor.
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var maxMinfact = 0i64
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var maxIdx: int
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for i in 0..responses.high:
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let minfact = ^responses[i] # Blocking read.
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echo &"For n = {Numbers[i]}, the lowest factor is {minfact}."
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if minfact > maxMinfact:
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maxMinfact = minfact
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maxIdx = i
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let result = Numbers[maxIdx]
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echo ""
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echo "The first number with the largest minimum prime factor is: ", result
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echo "Its factors are: ", result.factors(maxMinfact).join(", ")
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