제출 #667553

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
667553		mychecksedad	Fancy Fence (CEOI20_fancyfence)	C++17	12 / 100	1 ms	340 KiB

fancyfence

/* Author : Mychecksdead */
#include<bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using namespace std;
typedef long long int ll;
typedef long double ld;
#define MOD (1000000000+7)
#define MOD1 (998244353)
#define PI 3.1415926535
#define pb push_back
#define setp() cout << setprecision(15)
#define all(x) x.begin(), x.end()
#define debug(x) cerr << #x << " is " << x << '\n';
const int N = 1e6+100, M = 1e5+10, F = 2147483646, K = 20;

int n, ls[N], rs[N];
ll w[N], h[N], pref[N];

ll comb2(ll x){
    return (x*(x+1)/2) % MOD;
}
ll p(int l, int r){
    if(l > 0)
        return pref[r] - pref[l - 1];
    return pref[r];
}

void solve(){
    cin >> n;
    for(int i = 0; i < n; ++i) cin >> h[i];
    for(int i = 0; i < n; ++i) cin >> w[i];

    pref[0] = w[0];
    for(int i = 1; i < n; ++i) pref[i] = pref[i - 1] + w[i];

    deque<pair<int, int>> q;

    ls[0] = -1;
    q.pb({h[0], 0});
    for(int i = 1; i < n; ++i){
        while(!q.empty() && q.back().first >= h[i]) q.pop_back();
        if(!q.empty()) ls[i] = q.back().second;
        else ls[i] = -1;
        q.pb({h[i], i});
    }
    q.clear();
    rs[n - 1] = n;
    q.pb({h[n - 1], n - 1});
    for(int i = n - 2; i >= 0; --i){
        while(!q.empty() && q.back().first > h[i]) q.pop_back();
        if(!q.empty()) rs[i] = q.back().second;
        else rs[i] = n;
        q.pb({h[i], i});
    }
    ll ans = 0;
    for(int i = 0; i < n; ++i){
        ll a = (p(ls[i] + 1, i) * p(i, rs[i] - 1) % MOD);
        (ans += (a - comb2(w[i] - 1)) * comb2(h[i])) %= MOD;
    }
    cout << (ans + MOD) % MOD;
}




int main(){
    cin.tie(0); ios::sync_with_stdio(0);
    // freopen("in.txt", "r", stdin);
    int T = 1, aa;
    // cin >> T;aa=T;
    while(T--){
        // cout << "Case #" << aa-T << ": ";
        solve();
        cout << '\n';
    }
    return 0;
 
}

컴파일 시 표준 에러 (stderr) 메시지

fancyfence.cpp: In function 'int main()':
fancyfence.cpp:70:16: warning: unused variable 'aa' [-Wunused-variable]
   70 |     int T = 1, aa;
      |                ^~

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