mlkimg的博客

题目：The following iterative sequence is defined for the set of positive integers:n  n/2 (n is even)n  3n + 1 (n is odd)Using the rule above and starting with 13, we generate the following seque...

题目：Starting in the top left corner of a 22 grid, there are 6 routes (without backtracking) to the bottom right corner.How many routes are there through a 2020 grid? a=Array.new(21){Array.ne...

社区里有不少project euler的题解，自己也写了些，主要是为了体验ruby的简洁（不过Mathematica好像更简单）问题1：If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples i...

问题11：[/size][size=x-small;]What is the greatest product of four adjacent numbers in any direction (up, down, left, right, or diagonally) in the 2020 grid?（在20*20的矩阵中任意方向，即上下左右斜线反斜线，找出4个连续的数，使他们的积最大，输出...