Submission #766561

#	Time	Username	Problem	Language	Result	Execution time	Memory
766561		raysh07	Let's Win the Election (JOI22_ho_t3)	C++17	100 / 100	322 ms	364 KiB

Main

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define INF (int)1e18
#define f first
#define s second

mt19937_64 RNG(chrono::steady_clock::now().time_since_epoch().count());

void Solve() 
{
    int n, k; cin >> n >> k;
    
    vector <pair<int, int>> a(n);
    for (auto &x : a) {
        cin >> x.s >> x.f;
        if (x.f == -1) x.f = INF;
    }
    
    sort(a.begin(), a.end());
    double ans = INF;
    
    for (int i = 0; i <= k; i++){
        vector <double> dp(k + 1, INF); //how many A's taken 
        dp[0] = 0;
        
       // cout << "OKING " << i << "\n\n";
        for (int j = 0; j < n; j++){
            vector <double> ndp(k + 1, INF); 
            for (int j1 = 0; j1 <= k; j1++){
                if (j1 != k)
                ndp[j1 + 1] = min(ndp[j1 + 1], dp[j1] + (double)a[j].s / (i + 1));
                int pos = j + 1 - j1;
                if (pos < 1) continue;
                if (pos <= i) ndp[j1] = min(ndp[j1], dp[j1] + (double)a[j].f / pos);
                else ndp[j1] = min(ndp[j1], dp[j1]);
            }
            
            // cout << "LOL " << j << "\n";
            // for (auto &x : ndp) cout << x << " ";
            // cout << "\n";
            
            dp = ndp;
        }
        // cout << "\n";
        
        ans = min(ans, dp[k - i]);
    }
    
    cout << fixed << setprecision(10) << ans << "\n";
}

int32_t main() 
{
    auto begin = std::chrono::high_resolution_clock::now();
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int t = 1;
   // cin >> t;
    for(int i = 1; i <= t; i++) 
    {
        //cout << "Case #" << i << ": ";
        Solve();
    }
    auto end = std::chrono::high_resolution_clock::now();
    auto elapsed = std::chrono::duration_cast<std::chrono::nanoseconds>(end - begin);
    cerr << "Time measured: " << elapsed.count() * 1e-9 << " seconds.\n"; 
    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