摘要：
DescriptionIn 1742, Christian Goldbach, a German amateur mathematician, sent a letter to Leonhard Euler in which he made the following conjecture: Every even number greater than 4 can be written as the sum of two odd prime numbers.For example: 8 = 3 + 5. Both 3 and 5 are odd prime numbers. 20 = 3 + 阅读全文
2012年4月9日
摘要：
View Code #include <iostream>#include <cmath>#include <cstring>using namespace std;typedef struct move{ int from; int to;} move;int main(){ move m[400]; int shap[400]; int T, N; int x, y, res; cin>>T; while(T--) { memset(shap,0,sizeof(shap)); cin>>N; f... 阅读全文
摘要：
DescriptionSome positive integers can be represented by a sum of one or more consecutive prime numbers. How many such representations does a given positive integer have? For example, the integer 53 has two representations 5 + 7 + 11 + 13 + 17 and 53. The integer 41 has three representations 2+3+5+7+ 阅读全文
摘要：
来源：http://hi.baidu.com/hking1987/blog/item/3c9525f50db21d66ddc4749b.html素数还有很多东西需要学，先整理三种最简单的判断素数的方法，以后再深究补充。判断n是否为素数1、最简单的方法用n除以2-sqrt(n),有一个能除尽就不是素数，否则是素数。时间复杂度：O(sqrt(n))2、素数判断法：这种方法是对上面方法的改进，上面方法是对2-sqrt(n)之间的数进行判断是否能除尽，而因为有如下算术基本定理，可以减少判断量。算术基本定理：又称为素数的唯一分解定理，即：每个大于1的自然数均可写为素数的积，而且这些素因子按大小排列之后， 阅读全文
