Submission #917437

#	Time	Username	Problem	Language	Result	Execution time	Memory
917437		theghostking	Hacker (BOI15_hac)	C++17	100 / 100	105 ms	14024 KiB

hac

#include <bits/stdc++.h>
using namespace std;

deque<int> q;

void ins(int x){
    while (!q.empty() && q.back() > x){
        q.pop_back();
    }
    q.push_back(x);
}

void ers(int x){
    if (!q.empty() && q.front() == x){
        q.pop_front();
    }
}

int getmn(){
    return q.front();
}

int main() {
    int n;
    cin >> n;
    vector<int> a(2*n);
    for (int i = 0; i<n; i++){
        cin >> a[i];
        a[n+i] = a[i];
    }
    vector<int> res;
    int k = (n+1)/2;
    int sm = 0;
    for (int i = 0; i<k; i++){
        sm += a[i];
    }
    res.push_back(sm);
    for (int i = k; i<n+k-1; i++){
        sm -= a[i-k];
        sm += a[i];
        res.push_back(sm);
    }
    for (int i = 0; i<n; i++){
        res.push_back(res[i]);
    }
    vector<int> ans(n, 1e9);
    for (int i = 0; i<k; i++){
        ins(res[i]);
    }
    ans[k-1] = getmn();
    for (int i = k; i<2*n; i++){
        ers(res[i-k]);
        ins(res[i]);
        int ind = i; if (ind >= n) ind -= n;
        ans[ind] = getmn();
    }
    int mx = 0;
    for (auto u : ans){
        mx = max(mx,u);
    }
    cout << mx << '\n';
    return 0;
}

• Subtask 1: 20 / 20
• Subtask 2: 20 / 20
• Subtask 3: 20 / 20
• Subtask 4: 40 / 40