RSA算法 :首先, 找出三個數, p, q, r, 其中 p, q 是兩個相異的質數, r 是與 (p-1)(q-1) 互質的數...... p, q, r 這三個數便是 person_key，接著, 找出 m, 使得 r^m == 1 mod (p-1)(q-1)..... 這個 m 一定存在, 因為 r 與 (p-1)(q-1) 互質, 用輾轉相除法就可以得到了..... 再來, 計算 n = pq....... m, n 這兩個數便是 public_key ，編碼過程是, 若資料為 a, 將其看成是一個大整數, 假設 a < n.... 如果 a >= n 的話, 就將 a 表成 s 進位 (s
標簽：
person_key
RSA
算法
上傳時間：
2013-12-14
上傳用戶：zhuyibin
源代碼\用動態規劃算法計算序列關系個數
用關系"<"和"="將3個數a，b，c依次序排列時，有13種不同的序列關系：
a=b=c,a=b<c,a<b=v,a<b<c,a<c<b
a=c<b,b<a=c,b<a<c,b<c<a,b=c<a
c<a=b,c<a<b,c<b<a
若要將n個數依序列，設計一個動態規劃算法，計算出有多少種不同的序列關系，
要求算法只占用O(n),只耗時O(n*n).
標簽：
lt
源代碼
動態規劃
序列
上傳時間：
2013-12-26
上傳用戶：siguazgb
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
標簽：
government
streamline
important
alphabet
上傳時間：
2015-06-09
上傳用戶：weixiao99
