Hiho! is a serial contests we developed to help programmers improve their skills following some architecture. After the problems in "String" serial, we now focus on "Dynamic programming". One of the core idea of Dynamic programming is not to calculate what has been calculated, not to calculate what is no used, and Hi call this idea "Release Redundancy". But this kind of technique is learning required. So we collect some classic dynamic programming problem here, analysis the redundancy in it, summerize the its regularity. Hope it will help your programming thinking.

And this problem "Triangle of numbers" is one of the most classic problem in this serial. Hi and Ho first introduce an unperfect way to solve it - "Search with memory", then the reason and idea we used dynamic programming to slove it. Hope this will help you understand the connection between dynamic programming and forced search, and understand dynamic programming better~