杭电多校第十场 hdu6434 Count 欧拉函数打表 快速打表模板

Problem I. Count

Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 524288/524288 K (Java/Others)
Total Submission(s): 42    Accepted Submission(s): 16

Problem Description

Multiple query, for each n, you need to get
n i-1
∑ ∑ [gcd(i + j, i - j) = 1]
i=1 j=1

 

 

Input

On the first line, there is a positive integer T, which describe the number of queries. Next there are T lines, each line give a positive integer n, as mentioned above.
T<=1e5, n<=2e7

 

 

Output

Your output should include T lines, for each line, output the answer for the corre- sponding n.

 

 

Sample Input

4 978 438 233 666

 

 

Sample Output

194041 38951 11065 89963

 

 

Source

2018 Multi-University Training Contest 10

 

 

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题意：求下面这个式子的值

n i-1
∑ ∑ [gcd(i + j, i - j) = 1]
i=1 j=1

分析：按照上面那个式子直接暴力打表容易得到上面式子的含义是1-n以内偶数的欧拉函数值加上奇数的欧拉函数值除以2的和（注意要快速打表，运用素数快速打表）

AC代码：

#include 

　　

转载于:https://www.cnblogs.com/l609929321/p/9519403.html