【数论】 HDOJ 5407 CRB and Candies

#include <bits/stdc++.h>
using namespace std;
typedef long long LL;

const int maxn = 1000005;
const int N = 1000000;
const int mod = 1e9+7;

int val[maxn];
LL f[maxn];
LL g[maxn];
int p[maxn];

LL powmod(LL a, LL b)
{
LL res = 1, base = a;
while(b) {
if(b % 2) res = res * base % mod;
base = base * base % mod;
b /= 2;
}
return res;
}

void init()
{
for(int i = 2; i < maxn; i++) if(p[i] == 0)
for(int j = i + i; j < maxn; j += i) p[j] = 1;

for(int i = 2; i < maxn; i++) if(p[i] == 0)
for(LL j = (LL)i; j < maxn; j *= i)
val[j] = i;
f[1] = 1;
for(int i = 2; i < maxn; i++)
if(val[i]) f[i] = f[i-1] * val[i] % mod;
else f[i] = f[i-1];
for(int i = 1; i <= N; i++) g[i] = f[i+1] * powmod(i+1, mod-2) % mod;
}

int main()
{
init();
int _;
scanf("%d", &_);
while(_--) {
int x;
scanf("%d", &x);
printf("%lld\n", g[x]);
}

return 0;
}