I remember this problem, though -- IMO it's a poorly-designed one. You can make a really stupid assumption about the answer and it'll turn out to be correct and save you a hell of a lot of runtime. Similarly, the problem is more programmatical than mathematical. You can brute force it (using a non-naive approach) in just a couple seconds (given the stupid assumption).
Stuck on 152, which is silly because it should be easy
Just did number 15. I thought it was a little too easy; there wasn't even any programming needed to do this problem.
Starting in the top left corner of a 2x2 grid, there are 6 routes (without backtracking) to the bottom right corner. How many routes are there through a 20x20 grid?
Comment