Sunday, January 07, 2018

[lpeqbtnn] O(tetrate)

Define an algorithm whose running time is O(tetration(2,n)), the power tower of n 2s.  Or worse, describe a problem which requires that amount of time.  Are there interesting such problems?

Perhaps we do not think of such things because of the hopelessness of ever computing them.

Intimidating at a lesser scale is O(n!), growing faster than any exponential function (but less than 2-EXPTIME).  What problems require factorial time?

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