Submission #945799

#	Time	Username	Problem	Language	Result	Execution time	Memory
945799		thelegendary08	Fancy Fence (CEOI20_fancyfence)	C++17	0 / 100	62 ms	15264 KiB

fancyfence

#include<bits/stdc++.h>
#define vi vector<int>
#define vll vector<long long int>
#define vpii vector<pair<int,int>>
#define vpll vector<pair<long long int, long long int>>
#define pb push_back
#define f0r(i,n) for(int i = 0;i<n;i++)
using namespace std;
typedef long long int ll;
const int mod = 1e9 + 7;
const int mxn = 1e5 + 5;
const int lg = floor(log2(mxn));
ll w[mxn];
ll h[mxn];
ll minh[lg][mxn];
ll c2(ll x){
    return x * (x+1) / 2 % mod;
}
ll ans(ll w, ll h){
    return c2(w) * c2(h) % mod;
}
ll minq(int l, int r){
    int sz = r - l + 1;
    int curlg = floor(log2(sz));

    return min(minh[curlg][l], minh[curlg][r - (int)pow(2, curlg) + 1]);
}
int main(){
    int n;
    cin>>n;
    f0r(i,n)cin>>h[i];
    f0r(i,n)cin>>w[i];
    f0r(i,n)minh[0][i] = h[i];
    for(int l = 1;l<=floor(log2(n));l++){
        f0r(i, n - pow(l, 2) + 1){
            minh[l][i] = min(minh[l-1][i], minh[l-1][i + (int)pow(l-1, 2)]);
        }
    }
    ll dp[n+1];
    dp[0] = ans(w[0], h[0]);
    ll pref = 0;
    for(int i = 1;i<n;i++){

        /*
        ll rm = h[i];
        ll thing = 0;
        for(int j = i-1;j>=0;j--){
            rm = min(rm, h[j]);
            thing += c2(rm) * w[j] % mod * w[i] % mod;
        }
        */

        pref += c2(h[i-1]) * w[i-1] % mod;
        pref %= mod;

        dp[i] = ((dp[i-1] + ans(w[i], h[i])) % mod + (pref * w[i] % mod)) % mod;

    }
    /*
    ll wsum = 0;
    f0r(i,n){
        wsum += w[i];
    }
    wsum %= mod;
    */

    //for(auto u : dp)cout<<u<<' ';
    //cout<<'\n';
    cout<<dp[n-1];
}

• 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