Submission #995987

#	Time	Username	Problem	Language	Result	Execution time	Memory
995987		vyshniak_n	Let's Win the Election (JOI22_ho_t3)	C++17	100 / 100	835 ms	1010204 KiB

Main

//#pragma optimize("Ofast")
//#pragma optimize("unroll-loops")
//#pragma traget("avx,avx2")
 
#include <iostream>
#include <cmath>
#include <algorithm>
#include <stdio.h>
#include <cstdint>
#include <cstring>
#include <string>
#include <cstdlib>
#include <vector>
#include <bitset>
#include <map>
#include <queue>
#include <ctime>
#include <stack>
#include <set>
#include <list>
#include <random>
#include <deque>
#include <functional>
#include <iomanip>
#include <sstream>
#include <fstream>
#include <complex>
#include <numeric>
#include <cassert>
#include <array>
#include <tuple>
#include <unordered_map>
#include <unordered_set>
#include <thread>
 
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
 
#define el '\n'
#define ff first
#define ss second
#define pb push_back
#define pf push_front
#define popb pop_back
#define popf pop_front
#define point pair <ll, ll>
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
 
using namespace std;
 
#include <random>
mt19937 rnd(time(0));
 
const ll INF = 1e18 + 10;
const ll inf = 1e9 + 10;
const ll N = 5e2 + 10;
const ll mod = 998244353;
const ll LOG = 20;
const ll K = 1e3 + 20;

double dp[N][N][N];
ll n, k, a[N], b[N], order[N];

ld calc(ll x) {
    for (ll i = 1; i <= n; i++) {
        for (ll j = 0; j <= min(i, k); j++) {
            if (i == j) {
                for (ll cnt = 0; cnt <= min(j, x); cnt++) {
                    if (j) {
                        dp[i][j][cnt] = min(dp[i][j][cnt],
                                            dp[i - 1][j - 1][cnt] + (double)a[order[i]] / (double)(x + 1));
                    }
                    if (cnt && b[order[i]] != inf) {
                        dp[i][j][cnt] = min(dp[i][j][cnt],
                                            dp[i - 1][j - 1][cnt - 1] + (double)b[order[i]] / (double)(cnt));
                    }
                } 
            } else {
                dp[i][j][x] = dp[i - 1][j][x];
                if (j)
                    dp[i][j][x] = min(dp[i][j][x], dp[i - 1][j - 1][x] + (double)a[order[i]] / (double)(x + 1));
            }
        }
    }

    ld res = dp[n][k][x];

    for (ll i = 1; i <= n; i++) {
        for (ll j = 0; j <= min(i, k); j++) {
            if (i == j) {
                for (ll cnt = 0; cnt <= min(j, x); cnt++)
                    dp[i][j][cnt] = inf;
            } else {
                dp[i][j][x] = inf;
            }
        }
    }
    return res;
}
 
void solve() {
    cin >> n >> k;

    for (ll i = 1; i <= n; i++) {
        cin >> a[i] >> b[i];
        if (b[i] == -1)
            b[i] = inf;
    }

    for (ll i = 1; i <= n; i++)
        order[i] = i;

    sort(order + 1, order + n + 1, [&](const ll &i, const ll &j) -> bool {
        if (b[i] == b[j])
            return a[i] < a[j];
        return b[i] < b[j];
    });

    for (ll i = 0; i <= n; i++)
        for (ll j = 0; j <= n; j++)
            for (ll votes = 0; votes <= n; votes++)
                dp[i][j][votes] = inf;
    dp[0][0][0] = 0;

    ld ans = inf;
    for (ll i = 0; i <= k; i++)
        ans = min(ans, calc(i));

    cout << fixed << setprecision(10) << ans << el;
    return;
}
signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
 
    int tests = 1;
    //cin >> tests;
 
    while (tests--) 
        solve();
    return 0;
}
/*
*/

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 11 / 11
• Subtask 4: 12 / 12
• Subtask 5: 33 / 33
• Subtask 6: 11 / 11
• Subtask 7: 23 / 23