The government of a small but important country has decided that the alphabet needs to be streamlined and reordered. Uppercase letters will be eliminated. They will issue a royal decree in the form of a String of B and A characters. The first character in the decree specifies whether a must come ( B )Before b in the new alphabet or ( A )After b . The second character determines the relative placement of b and c , etc. So, for example, "BAA" means that a must come Before b , b must come After c , and c must come After d .
Any letters beyond these requirements are to be excluded, so if the decree specifies k comparisons then the new alphabet will contain the first k+1 lowercase letters of the current alphabet.
Create a class Alphabet that contains the method choices that takes the decree as input and returns the number of possible new alphabets that conform to the decree. If more than 1,000,000,000 are possible, return -1.
Definition
按照Clifford A . Shaffer《數(shù)據(jù)結(jié)構(gòu)與算法分析（第二版）》指導，用C#實現(xiàn)的B+樹，接口定義良好。最好重寫“從文件載入新建樹部分”的代碼以提高建樹效率。實現(xiàn)細節(jié)之一：當“需要插入子節(jié)點的節(jié)點”已滿而相鄰節(jié)點未滿時會平分兩者節(jié)點而不是分裂該節(jié)點。
漢諾塔！！！
Simulate the movement of the Towers of Hanoi puzzle Bonus is possible for using animation
eg. if n = 2 A→B A→C B→C
if n = 3 A→C A→B C→B A→C B→A B→C A→C
