31 lines
788 B
Io
31 lines
788 B
Io
HailStone := Object clone
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HailStone sequence := method(n,
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if(n < 1, Exception raise("hailstone: expect n >= 1 not #{n}" interpolate))
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n = n floor // make sure integer value
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stones := list(n)
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while (n != 1,
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n = if(n isEven, n/2, 3*n + 1)
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stones append(n)
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)
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stones
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)
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if( isLaunchScript,
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out := HailStone sequence(27)
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writeln("hailstone(27) has length ",out size,": ",
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out slice(0,4) join(" ")," ... ",out slice(-4) join(" "))
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maxSize := 0
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maxN := 0
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for(n, 1, 100000-1,
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out = HailStone sequence(n)
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if(out size > maxSize,
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maxSize = out size
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maxN = n
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)
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)
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writeln("For numbers < 100,000, ", maxN,
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" has the longest sequence of ", maxSize, " elements.")
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)
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