Description:
Count the number of prime numbers less than a non-negative number, n
[思路]
素数不能被比它小的整数整除, 建一个boolean 数组, 从2开始, 把其倍数小于N的都删掉.
注意 inner loop从i开始, 比i小的会在以前就被check过.
[CODE]
pu...
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其他好文 时间:
2015-04-29 08:43:31
阅读次数:
95
题目链接:count-primes
Description:
Count the number of prime numbers less than a non-negative number, n
public class Solution {
public int countPrimes(int n) {
if(n <= 2) return 0;
Lis...
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其他好文 时间:
2015-04-28 23:02:38
阅读次数:
225
题目:leetcode
Count Primes
Description:
Count the number of prime numbers less than a non-negative number, n
分析:
求出比n小的素数的个数,这个问题可以用排除法做,参考http://www.cnblogs.com/grandyang/p/4462810.html
...
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其他好文 时间:
2015-04-28 23:01:22
阅读次数:
287
Description:
Count the number of prime numbers less than a non-negative number, n
提示晒数法:
http://en.wikipedia.org/wiki/Sieve_of_Eratosthenes
https://primes.utm.edu/howmany.html
别人的代码:
...
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其他好文 时间:
2015-04-28 22:49:39
阅读次数:
238
题目:You are given two linked lists representing two non-negative numbers. The digits are stored in reverse order and each of their nodes contain a sing...
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其他好文 时间:
2015-04-28 22:48:34
阅读次数:
167
Description:Count the number of prime numbers less than a non-negative number,nclick to show more hints.Credits:Special thanks to@mithmattfor adding t...
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编程语言 时间:
2015-04-28 22:41:35
阅读次数:
184
Description:Count the number of prime numbers less than a non-negative number,nReferences:How Many Primes Are There?Sieve of Eratosthenes由于一个合数总是可以分解成...
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其他好文 时间:
2015-04-28 22:39:09
阅读次数:
164
Given n non-negative integers a1, a2, ..., an, where each represents a point at coordinate (i, ai). n vertical lines are drawn such that the two endpo...
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编程语言 时间:
2015-04-28 22:28:27
阅读次数:
202
Count Primes
Description:
Count the number of prime numbers less than a non-negative number, n
解题思路:
题意为求小于n的质数的个数。有两种方法:
1、naive办法,对小于n的每个数,检查是否为质数。而检查m是否为质数,需要验证是否都不能被2~pow(m, 0.5)整...
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其他好文 时间:
2015-04-28 21:07:26
阅读次数:
155
Count the number of prime numbers less than a non-negative number,n题意:求小于n的所有素数的个数。思路:1. 范围在1~n-1,求先把2的倍数删除,再把3的倍数删除,再把5的倍数删除。。。每次都把集合中最小元素的倍数删除,多次循环之...
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其他好文 时间:
2015-04-28 17:52:50
阅读次数:
112