oracl 和db2 常用语法比较: 1、取前N条记录 Oracle:Select * from TableName where rownum <= N; DB2:Select * from TableName fetch first N rows only; 2、取得系统日期 Oracle:Select sysdate from dual; DB2:Select current timestamp from sysibm.sysdummy1; 3、空值转换 Oracle:Select
计算浮点数的n次方,在北京大学的OJ网站上的题目,已经提交AC。可以作为参考。
原题如下:
Descr iption
Problems involving the computation of exact values of very large magnitude and precision are common. For example, the computation of the national debt is a taxing experience for many compute
本文实例讲述了Python素数检测的方法。分享给大家供大家参考。具体如下:
因子检测:
检测因子,时间复杂度O(n^(1/2))
def is_prime(n):
if n < 2:
return False
for i in xrange(2, int(n**0.5+1)):
if n%i == 0:
return False
return True
费马小定理:
如果n是一个素数,a是小于n的任意正整数,那么a的n次方与a模n同余
实现方法: