Submission #1121190

#	Time	Username	Problem	Language	Result	Execution time	Memory
1121190		thangdz2k7	Let's Win the Election (JOI22_ho_t3)	C++17	100 / 100	79 ms	4868 KiB

Main

// author : thembululquaUwU
// 3.9.2024

#include <bits/stdc++.h>
#define pb push_back
#define fi first
#define se second
#define endl '\n'

using namespace std;
using ll = long long;
using ii = pair <int, int>;
using vi = vector <int>;

const int N = 5e2 + 5;
const int mod = 1e9 + 7;

int n, k;
pair <int, int> state[N];

namespace subtask1{
    const int sub = 105;

    using lb = long double;

    const lb inf = 1e9;

    lb dp[sub][sub][sub];

    void solve(){

        lb ans = inf;

        for (int fix = 0; fix < k; ++ fix){
            for (int i = 0; i <= fix; ++ i){
                for (int j = 0; j <= k - fix; ++ j) dp[0][i][j] = inf;
            }
            dp[0][0][0] = 0;
            for (int i = 1; i <= n; ++ i){
                lb a = state[i].se, b = state[i].fi;
                for (int j = 0; j <= fix; ++ j){
                    for (int t = 0; t <= k - fix; ++ t){
                        dp[i][j][t] = dp[i - 1][j][t];
                        if (t) dp[i][j][t] = min(dp[i][j][t], dp[i - 1][j][t - 1] + a / (fix + 1));
                        if (j && b != -1) dp[i][j][t] = min(dp[i][j][t], dp[i - 1][j - 1][t] + b / j);
                    }
                }
            }

            ans = min(ans, dp[n][fix][k - fix]);
        }

        cout << fixed << setprecision(10) << ans;
    }
}

namespace ac{

    using lb = long double;

    void minl(lb &a, lb b){
        a = min(a, b);
    }

    const lb inf = 1e9;

    lb dp[N][N], ans = inf;

    lb calc(int fix){
        for (int i = 0; i <= n; ++ i)
            for (int j = 0; j <= k; ++ j) dp[i][j] = inf;
        dp[0][0] = 0;
        for (int i = 0; i < n; ++ i){
            lb a = state[i + 1].se, b = state[i + 1].fi;
            for (int j = 0; j <= min(k, i); ++ j) if (dp[i][j] != inf){
                if (j < fix){
                    minl(dp[i + 1][j], dp[i][j] + a / (fix + 1));
                    if (j < fix - 1) minl(dp[i + 1][j + 1], dp[i][j] + b / (j + 1));
                    else minl(dp[i + 1][i + 1], dp[i][j] + b / (j + 1));
                }
                else {
                    minl(dp[i + 1][j], dp[i][j]);
                    minl(dp[i + 1][j + 1], dp[i][j] + a / (fix + 1));
                }
            }
        }

        ans = min(ans, dp[n][k]);
        return dp[n][k];
    }

    void solve(){
        ans = calc(0);
        int l = 0, r = k - 2;
        while (l <= r){
            int mid = l + r >> 1;
            if (calc(mid) > calc(mid + 1)) l = mid + 1;
            else r = mid - 1;
        }

        cout << fixed << setprecision(10) << ans;
    }
}

void solve(){
    cin >> n >> k;
    for (int i = 1; i <= n; ++ i){
        cin >> state[i].se >> state[i].fi;
        if (state[i].fi == -1) state[i].fi = mod;
    }

    sort(state + 1, state + n + 1);

    ac::solve();

    //if (n <= 100) subtask1::solve();
    //else ac::solve();
}

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

    int t = 1; // cin >> t;
    while (t --) solve();
    return 0;
}

Compilation message (stderr)

Main.cpp: In function 'void ac::solve()':
Main.cpp:96:25: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   96 |             int mid = l + r >> 1;
      |                       ~~^~~

• 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