Submission #74681810

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Source Code Expand

#include <iostream>
#include <vector>
using namespace std;

const int MOD=998244353;
const int MX=5e5+10;

long long a[MX],b[MX],sa[MX];

long long f(int n,int k){
    long long r=0;
    for(int l=1;l<=n;){
        int q=l/k;
        int rr=min((q+1)*k-1,n);
        r=(r+q*(sa[rr]-sa[l-1]+MOD)%MOD)%MOD;
        l=rr+1;
    }
    return r;
}

int main(){
    ios::sync_with_stdio(0);cin.tie(0);
    int n,m;cin>>n>>m;
    for(int i=1;i<=n;++i)cin>>a[i],a[i]%=MOD;
    for(int i=1;i<=m;++i)cin>>b[i],b[i]%=MOD;
    for(int i=1;i<=n;++i)sa[i]=(sa[i-1]+a[i])%MOD;
    long long s1=0;
    for(int i=1;i<=n;++i)s1=(s1+a[i]*i%MOD)%MOD;
    long long sb=0;
    for(int i=1;i<=m;++i)sb=(sb+b[i])%MOD;
    s1=s1*sb%MOD;
    long long s2=0;
    for(int j=1;j<=m;++j){
        long long c=f(n,j);
        long long v=b[j]*j%MOD;
        v=v*c%MOD;
        s2=(s2+v)%MOD;
    }
    long long ans=(s1-s2+MOD)%MOD;
    cout<<ans<<'\n';
    return 0;
}

Submission Info

Judge Result