题目描述
Consider a triangle of integers, denoted by T. The value at (r, c) is denoted by Tr,c , where 1 ≤ r and 1 ≤ c ≤ r. If the greatest common divisor of r and c is exactly 1, Tr,c = c, or 0 otherwise. Now, we have another triangle of integers, denoted by S. The value at (r, c) is denoted by S r,c , where 1 ≤ r and 1 ≤ c ≤ r. S r,c is defined as the summation Here comes your turn. For given positive integer k, you need to calculate the summation of elements in k-th row of the triangle S.
输入
The first line of input contains an integer t (1 ≤ t ≤ 10000) which is the number of test cases. Each test case includes a single line with an integer k described as above satisfying 2 ≤ k ≤ 10^8 .
输出
For each case, calculate the summation of elements in the k-th row of S, and output the remainder when it divided by 998244353.
样例输入
223
样例输出
15
所有与k不互质的数的贡献就是p1的倍数的贡献+p2的倍数的贡献+...+pu的倍数的贡献-p1*p2的倍数的贡献-p1*p3的倍数的贡献-...+p1*p2*p3的倍数的贡献+......以p1的倍数的贡献为例,他的贡献是(p1*1)^2+(p1*2)^2+...+(p1*[k/p1])^2,就是p^2*(1^2+2^2+...+(p1*[k/p1])^2
#include#define ll long longusing namespace std;const int N=1e4+10;const int p=998244353;int T,cnt,k;bool vis[N];int prime[N],a[N];void pre(){ for (int i=2;i >=1; } return ret;}int fund(int n){ int sum=0; for (int i=1;i<=cnt;i++) { if (prime[i]>n) break; if (n%prime[i]==0) { a[sum++]=prime[i]; while (n%prime[i]==0) n/=prime[i]; } } if (n>1) a[sum++]=n; return sum;}void solve(int n){ ll nn=(ll)n; ll inv6=poww(6,p-2); ll ans=nn%p*(nn+1)%p*(2*nn+1)%p*inv6%p; int sum=fund(n); ll tmp=0; for (int i=1;i<(1< >j)&1) { x=x*(ll)a[j]%p; s++; } } ll t=(ll)n/x; if (s&1) tmp=(tmp+x*x%p*t%p*(t+1)%p*(2*t+1)%p*inv6%p)%p; else tmp=((tmp-x*x%p*t%p*(t+1)%p*(2*t+1)%p*inv6%p)%p+p)%p; } ans=((ans-tmp)%p+p)%p; printf("%lld\n",ans);}int main(){ pre(); scanf("%d",&T); while (T--) { scanf("%d",&k); solve(k); } return 0;}