# | Submission time | Handle | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
1104130 | 2024-10-23T01:54:08 Z | ezzzay | Fancy Fence (CEOI20_fancyfence) | C++14 | 0 ms | 0 KB |
#include<bits/stdc++.h> using namespace std; #define ff first #define ss second #define pb push_back #define int long long const int N=3e5+5; int h[N]; int w[N]; int mod=1e9+7; int modd(int n){ return (n%mod+mod)%mod; } int cal(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--){ ans+=calc(h[i],w[i])-calc(h[i-1],w[i]); ans=modd(ans); } cout<<ans; }