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 This article is came from a discussion in forum, it is a problem to computing f(n) that f(n) = fibonacci[i-1]*fibonacci[i]*fibonacci[i+1]. Apparently the vaule of f(n) is too huge to represented by p

The article is about the design of algorithm for n queen problem. The intention of this article is from an excise of an algorithm book: >. This backtracking algorithm is interesting, so I decide to re

I think it is necessary to analyze the efficiency class before optimize it. It is difficult to estimate the efficiency class accurately because the each of recurrence running time is different. So I u

Given a solution and image the chess board is transparent. Another solution can be got immediately by turn this chess board (left-right turn). That is, look the solution from other side of chess board

The backtracking algorithm of n queen problem can be improved by space and time trade-off further. The consideration of positions occupancy is attained by duplicate_array and two integrals. Note that

I have tried to utilizing the “1 generates others 7” characteristic of n queen problem. Finally, I found that it must have the knowledge of relationship between n and numbers of solutions. The program

在论坛上看到有人问这个，觉得其中一个有点意思就回了。顺便把回的内容发在这里。题目是这样的：/////////////////////////////////////////////////////////////////////  answer beginning  //////////////////////////////////////////////////////////////

 A*算法作为一种启发式寻路算法比一般的shortest path finding比如dijkstra算法更快，但是由于启发式的原因，其结果不一定是最优的。 只有在一定的条件下，A*算法才能保证找到最优解。这个条件是A*算法的启发式h(n)必须是consistency或者monotonicity的：A heuristic h(n) is consistent if, for every