题意：
思路：From https://blog.csdn.net/CSDNjiangshan/article/details/81536536
1 #include<cstdio> 2 #include<cstring> 3 #include<string> 4 #include<cmath> 5 #include<iostream> 6 #include<algorithm> 7 #include<map> 8 #include<set> 9 #include<queue> 10 #include<vector> 11 #include<bitset> 12 using namespace std; 13 typedef long long ll; 14 typedef unsigned int uint; 15 typedef unsigned long long ull; 16 typedef pair<int,int> PII; 17 typedef vector<int> VI; 18 #define fi first 19 #define se second 20 #define MP make_pair 21 #define N 110000000 22 #define M 51 23 #define MOD 1000000007 24 #define eps 1e-8 25 #define pi acos(-1) 26 #define oo 3e14 27 28 uint n,a,b,c,d; 29 bitset<N> p; 30 31 uint f(uint x) 32 { 33 return a*x*x*x+b*x*x+c*x+d; 34 } 35 36 uint calc(uint x) 37 { 38 uint k=n; 39 uint ans=0; 40 while(k) 41 { 42 ans+=k/x;; 43 k/=x; 44 } 45 ans*=f(x); 46 return ans; 47 } 48 49 int main() 50 { 51 scanf("%u%u%u%u%u",&n,&a,&b,&c,&d); 52 ull ans=calc(2)+calc(3); 53 p.reset(); 54 for(uint i=5;i<=n;i++) 55 { 56 if(i%2==0||i%3==0) continue; 57 if(p[i/3]==0) 58 { 59 ans+=calc(i); 60 for(uint j=2;j<=n/i;j++) 61 { 62 if(i*j%2==0||i*j%3==0) continue; 63 p[i*j/3]=1; 64 } 65 } 66 } 67 printf("%u",ans); 68 return 0; 69 }