Submission #1104133

#	Time	Username	Problem	Language	Result	Execution time	Memory
1104133		ezzzay	Fancy Fence (CEOI20_fancyfence)	C++14	0 / 100	2 ms	2384 KiB

fancyfence

#include<bits/stdc++.h>
using namespace std;
#define ff first
#define ss second
#define pb push_back
const int N=3e5+5;
int h[N];
int w[N];
int ps[N];
int mod=1e9+7;
int modd(int n){
    return (n%mod+mod)%mod;
}
int calc(int a, int b){
    int f=(a*(a+1))%mod*((mod+1)/2)%mod;
    int s=(b*(b+1))%mod*((mod+1)/2)%mod;
    return (f*s)%mod;
}
signed main(){
    int n;
    cin>>n;
    for(int i=1;i<=n;i++){
        cin>>h[i];
    }
    for(int i=1;i<=n;i++){
        cin>>w[i];
    }
    int ans=0;
    for(int i=n;i>=1;i--){
        ps[i]=ps[i+1]+w[i];
        ans+=calc(h[i],ps[i])-calc(h[i-1],ps[i]);
        ans=modd(ans);
    }
    cout<<ans;
}

• Subtask 1: 0 / 0
• Subtask 2: 0 / 12
• Subtask 3: 0 / 13
• Subtask 4: 0 / 15
• Subtask 5: 0 / 15
• Subtask 6: 0 / 18
• Subtask 7: 0 / 27