Submission #1253602

#	Time	Username	Problem	Language	Result	Execution time	Memory
1253602		norman165	Let's Win the Election (JOI22_ho_t3)	C++20	61 / 100	2594 ms	6072 KiB

Main

#include <bits/stdc++.h>

#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define int long long
#define yes() cout << "YES\n"
#define no() cout << "NO\n"

using namespace std;
using ll = long long;
using ull = unsigned long long;
using ld = long double;

const int inf = 1e18;
const int mod = 1e9 + 7;
const int maxn = 1e6 + 10;
const int mod1 = 998244353;
const int mod2 = 1e18 + 1;
const int mod3 = 1e9 + 9;
const int mod4 = 333333333;
const int mod5 = 200000;
const int mod6 = 10007;
const int k = 300;
const int w = 1e5;
const ld EPS = 1e-8;

int LOG = 30;

ld dp[2][510][510];

void solve() {
    int n, k1;
    cin >> n >> k1;

    vector<pair<ld, ld>> a(n);
    for (auto& i : a) {
        cin >> i.first >> i.second;
        if (i.second == -1) i.second = inf;
    }

    sort(all(a), [](pair<ld, ld> a, pair<ld, ld> b) {
        return a.second < b.second || (a.second == b.second && a.first < b.first);
    });

    ld ans = inf;

    auto f = [&](int x) {
        for (int i = 0; i < 2; i++) {
            for (int j = 0; j <= x; j++) {
                for (int k = 0; k <= k1 - x; k++) dp[i][j][k] = inf;
            }
        }
        dp[0][0][0] = 0;

        for (int i = 1; i <= n; i++) {
            int i1 = (i & 1);

            for (int j = 0; j <= x; j++) {
                for (int k = 0; k <= k1 - x; k++) {
                    dp[i1][j][k] = dp[i1 ^ 1][j][k];

                    ld cnt1 = j;
                    ld cnt2 = x;
                    if (j > 0) dp[i1][j][k] = min(dp[i1][j][k], dp[i1 ^ 1][j - 1][k] + a[i - 1].second / cnt1);
                    if (k > 0) dp[i1][j][k] = min(dp[i1][j][k], dp[i1 ^ 1][j][k - 1] + a[i - 1].first / (cnt2 + 1));
                }
            }
        }

        return dp[n & 1][x][k1 - x];
    };

    int l = 0;
    int r = k1;

    while (r - l > 1) {
        int m = (l + r) / 2;

        if (f(m) <= f(m + 1)) r = m;
        else l = m;
    }

    for (int i = max(0ll, l - 1); i <= min(k1, l + 1); i++) ans = min(ans, f(i));
    cout << ans << "\n";
}

signed main() {
    cout.precision(16);

    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int t = 1;
    // cin >> t;

    while (t--) {
        solve();
    }
}

• Subtask 1: 5 / 5
• Subtask 2: 0 / 5
• Subtask 3: 11 / 11
• Subtask 4: 12 / 12
• Subtask 5: 33 / 33
• Subtask 6: 0 / 11
• Subtask 7: 0 / 23