Submission #871469

#	Time	Username	Problem	Language	Result	Execution time	Memory
871469		HorizonWest	Let's Win the Election (JOI22_ho_t3)	C++17	0 / 100	550 ms	1048576 KiB

Main

#include <bits/stdc++.h>
using namespace std;
 
#define endl '\n'
#define db double
#define ll __int128
#define int long long
#define pb push_back
#define fs first
#define sd second
#define Mod long(1e9 + 7)
#define all(x) x.begin(), x.end()
#define unvisited long(-1)
#define Eps double(1e-9)
#define _for(i, n) for(int i = 0; i < (n); i++)
#define dbg(x) cout << #x ": " << x << endl;
 
const int Max = 1e6 + 7, Inf = 1e9 + 7;
 
void print(bool x) { cout << (x ? "YES" : "NO") << endl; }
 
string tostring (__int128 x)
{
    string ans = "";
    while(x > 0)
    {
        ans += (x % 10 + '0');
        x /= 10;
    }
    reverse(all(ans));
    return ans;
}
 
void printdb(double ans, int k)
{
    cout << setiosflags(ios::fixed)
         << setiosflags(ios::showpoint)
         << setprecision(k) << ans << endl;
}

pair <db, db> fmin(pair<db, db> a, pair <db, db> b, db j)
{
    if(db(a.fs + a.sd / j) < db(b.fs + b.sd / j))
        return a; 
    else   
        return b; 
}
 
void solve()
{
    int n, m; cin >> n >> m; 
    vector <pair<db, db>> v(n); 
    for(auto& u : v) 
    {
        cin >> u.sd >> u.fs;
        if(u.fs == -1) u.fs = Inf;  
    } 
    sort(all(v)); db ans = Inf; 
 
    vector <vector<vector<pair<db, db>>>> dp(n + 5, vector <vector<pair<db, db>>> (
        m + 5, vector <pair<db, db>> (m + 5, { Inf, Inf })
    )); dp[0][1][0].fs = dp[0][1][0].sd = 0.000;  
    
    for(db i = 0; i < n; i++)
    {
        for(db j = 1; j <= m; j++)
        {
            for(db k = 0; k <= m; k++)
            {
                pair <db, db> f1 = dp[i][j][k], f2 = dp[i][j][k]; //{ dp[i][j][k].fs, dp[i][j][k].sd + v[i].sd }
                
                f1.sd += v[i].sd; f2.fs += v[i].fs; 

                dp[i+1][j][k] = fmin(dp[i+1][j][k], dp[i][j][k], j);  
                dp[i+1][j][k+1] = fmin(dp[i+1][j][k+1], f1, j); 
                
                if(v[i].fs != Inf)
                {
                    dp[i+1][j+1][k+1] = fmin(dp[i+1][j+1][k+1], f2, j + 1); // dp[i][j][k] + v[i].fs / j 
                } 
            }
            ans = min(ans, dp[i+1][j][m].fs + dp[i+1][j][m].sd / j); 
        }
    }

    printdb(ans, 5); 
}
 
int32_t main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
 
    int Q = 1; //cin >> Q;
 
    while (Q--)
    {
        solve();
    }
 
    return 0;
}

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