题目:
E(N) = |{i | gcd(N, i) = 1, 1 <= i <= N}|F(N) = |{i | N % i = 0, 1 <= i <= N}|
求有多少区间段[l,r](1<=l<=r<=n),满足上式,输出,
打表后,发现29以后都是10 ^-^
#include<iostream>
#include<cstdio>
using namespace std;
int main()
{
int answer[31]={0,1,1,2,2,4,5,5,6,6,7,7,7,7,7,7,7,7,8,8,8,8,8,8,9,9,9,9,9,9,10};
int n,c;
scanf("%d",&c);
for(int t=1;t<=c;t++)
{
scanf("%d",&n);
if(n<30)
printf("Case %d: %d\n",t,answer[n]);
......
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