제출 #855495

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
855495		MisterReaper	Seesaw (JOI22_seesaw)	C++17	0 / 100	0 ms	348 KiB

seesaw

//author: Ahmet Alp Orakci
#include <bits/stdc++.h>
using namespace std;
using i64 = long long;
#define int i64

#define ONLINE_JUDGE
void solve() {
    int n;
    cin >> n;

    vector <int> vec(n +1);
    for(int i = 1; i <= n; i++)
        cin >> vec[i];

    vector <int> pref = vec;
    for(int i = 1; i <= n; i++) 
        pref[i] += pref[i -1];

    array <double, 2> dp[n +1][n +1];
    for(int i = 1; i <= n; i++)
        dp[i][i] = {double(vec[i]), double(vec[i])};

    for(int i = 1; i <= n; i++) {
        for(int j = 1; j + i <= n; j++) {
            array <double, 2> l = dp[j][j + i -1], r = dp[j +1][j + i];
            double nw = (1.f * pref[j + i] - pref[j -1]) / (i +1);
            //cerr << j << " " << j + i << " :: " << nw << "\n";
            l[0] = min(l[0], nw); l[1] = max(l[1], nw);
            r[0] = min(r[0], nw); r[1] = max(r[1], nw);

            if(l[1] - l[0] < r[1] - r[0]) {
                dp[j][j + i] = l;
            } else {
                dp[j][j + i] = r;
            }
        }
    }

    /*
    for(int i = 1; i <= n; i++) {
        for(int j = i; j <= n; j++) {
            cerr << "{ " << dp[i][j][0] << ", " << dp[i][j][1] << " }" << " \n"[j == n];
        }
    }
    */

    cerr << setprecision(9) << dp[1][n][0] << " " << dp[1][n][1] << "\n";
    cout << setprecision(9) << dp[1][n][1] - dp[1][n][0];

    return;
}

signed main() {
    #ifndef ONLINE_JUDGE
        freopen(".in", "r", stdin);
        freopen(".out", "w", stdout);
    #endif

    ios_base::sync_with_stdio(false);
    cin.tie(NULL); cout.tie(NULL);

    int t = 1; //cin >> t;
    for(int i = 1; i <= t; i++) {
        solve();
    }

    return 0;
}

• Subtask 1: 0 / 1
• Subtask 2: 0 / 33
• Subtask 3: 0 / 33
• Subtask 4: 0 / 33