Submission #869499

#	Time	Username	Problem	Language	Result	Execution time	Memory
869499		lalig777	Fancy Fence (CEOI20_fancyfence)	C++14	0 / 100	1 ms	540 KiB

fancyfence

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

const int m=1e9+7;

int main(){
    int n;
    cin>>n;
    long long int res=0;
    vector<long long int>horizontales(n+1);
    vector<long long int>alturas(n);
    stack<int>pila1;
    stack<int>pila2;
    stack<int>pila3;
    vector<pair<int,int>>siguiente(n, make_pair(-1, n));
    vector<int>v(n, -1);
    for (int i=0; i<n; i++) cin>>alturas[i];
    horizontales[0]=0;
    int x;
    for (int i=0; i<n; i++){
        cin>>x;
        horizontales[i+1]=(horizontales[i]+x)%m;
    }for (int i=0; i<n; i++){
        while (!pila1.empty()){
            if (alturas[pila1.top()]>=alturas[i]) pila1.pop();
            else{
                siguiente[i].first=pila1.top();
                break;
            }
        }pila1.push(i);
        while (!pila2.empty()){
            if (alturas[pila2.top()]>=alturas[n-i-1]) pila2.pop();
            else{
                siguiente[n-i-1].second=pila2.top();
                break;
            }
        }pila2.push(n-i-1);
        while (!pila3.empty()){
            if (alturas[pila3.top()]<=alturas[i]){
                v[i]=pila3.top();
                break;
            }else pila3.pop();
        }pila3.push(i);
    }
    long long int left=0, right, top, bottom=0;
    long long int h, w;
    for (int i=0; i<n; i++){
        left=horizontales[i]+m-horizontales[siguiente[i].first+1];
        left%=m;
        right=horizontales[siguiente[i].second]+m-horizontales[siguiente[i].first+1];
        right%=m;
        top=alturas[i];
        if (v[i]==-1) bottom=0;
        else bottom=alturas[v[i]];
        long long int a, b;
        a=right*(right+1)%m;
        b=left*(left+1)%m;
        w=(a+m-b)/2;
        w%=m;
        a=top*(top+1)%m;
        b=bottom*(bottom+1)%m;
        h=(a+m-b)/2;
        h%=m;
        res+=(w*h)%m;
        res%=m;
    }cout<<res<<endl;

    return 0;
}

• 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