Submission #791357

#	Time	Username	Problem	Language	Result	Execution time	Memory
791357		ttamx	Fancy Fence (CEOI20_fancyfence)	C++14	30 / 100	1087 ms	2004 KiB

fancyfence

#include<bits/stdc++.h>

using namespace std;

typedef long long ll;

const int N=1e5+5;
const ll mod=1e9+7;
const ll inv2=5e8+4;

int n;
ll h[N],w[N];
ll ans;

ll calc(ll x){
    x%=mod;
    return x*(x+1)%mod*inv2%mod;
}

int main(){
    cin.tie(nullptr)->sync_with_stdio(false);
    cin >> n;
    for(int i=1;i<=n;i++)cin >> h[i];
    for(int i=1;i<=n;i++)cin >> w[i];
    for(int i=1;i<=n;i++){
        ll rmq=h[i];
        ans+=calc(w[i])*calc(h[i])%mod;
        ans%=mod;
        for(int j=i-1;j>=1;j--){
            rmq=min(rmq,h[j]);
            ans+=calc(rmq)*w[i]%mod*w[j]%mod;
            ans%=mod;
        }
    }
    cout << ans;
}

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