Submission #599608

#	Time	Username	Problem	Language	Result	Execution time	Memory
599608		fvogel499	Boarding Passes (BOI22_passes)	C++17	60 / 100	2058 ms	10032 KiB

passes

/*
 * File created on 07/19/2022 at 18:21:46.
 * Link to problem: 
 * Description: 
 * Time complexity: O()
 * Space complexity: O()
 * Status: ---
 * Copyright: Ⓒ 2022 Francois Vogel
*/

#include <bits/stdc++.h>

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

#define pii pair<int, int>
#define f first
#define s second

#define vi vector<int>
#define all(x) x.begin(), x.end()
#define size(x) (int)((x).size())
#define pb push_back
#define ins insert
#define cls clear

#define int ll
#define ll long long
#define ld long double

typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;

const int inf = 1e18;

signed main() {
    cin.tie(0);
    ios_base::sync_with_stdio(0);

    cout.precision(20);

    string b;
    cin >> b;
    const int n = size(b);
    int gK = 0;
    for (char i : b) if (i-'A'+1 > gK) gK = i-'A'+1;
    vi per [gK];
    for (int i = 0; i < n; i++) {
        per[b[i]-'A'].pb(i);
    }
    ld cost [gK][1<<gK];
    for (int i = 0; i < gK; i++) for (int j = 0; j < (1<<gK); j++) if (!((j>>i)&1)) {
        int pref [n];
        for (int k = 0; k < n; k++) pref[k] = (j>>(b[k]-'A'))&1;
        for (int k = 1; k < n; k++) pref[k] += pref[k-1];
        cost[i][j] = 0;
        for (int k = 0; k < size(per[i]); k++) {
            ld dl = k;
            ld dr = size(per[i])-k-1;
            ld cl = 0;
            if (per[i][k]) cl = pref[per[i][k]-1];
            ld cr = pref[n-1]-pref[per[i][k]];
            cost[i][j] += min(cl+dl/(ld)(2), cr+dr/(ld)(2));
        }
    }
    ld dp [1<<gK];
    dp[(1<<gK)-1] = 0;
    for (int i = (1<<gK)-2; i >= 0; i--) {
        dp[i] = inf;
        for (int j = 0; j < gK; j++) if (!((i>>j)&1)) {
            dp[i] = min(dp[i], dp[i|(1<<j)]+cost[j][i]);
        }
    }
    cout << dp[0];

    cout.flush();
    int d = 0;
    d++;
}

• Subtask 1: 5 / 5
• Subtask 2: 25 / 25
• Subtask 3: 30 / 30
• Subtask 4: 0 / 40