in reply to Shift, Pop, Unshift and Push with Impunity!
O(2^n) - only the slowest algorithms take this long to run. Traveling salesman problem, etc.
I could be wrong, but isn't the Travelling Salesman problem O(n!) - i.e. much worse than O(2^n) for n>3.
Travelling Salesman is an NP-complete problem, i.e. it cannot be solved in a measure of time which is a polynomial function of the number of data points.
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