Submission #794830

#	Time	Username	Problem	Language	Result	Execution time	Memory
794830		gun_gan	Let's Win the Election (JOI22_ho_t3)	C++17	61 / 100	2610 ms	1008548 KiB

Main

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
 
const int MX = 505;
 
int N, K;
int a[MX], b[MX];
double dp[MX][MX][MX];
 
vector<pair<int, int>> v;

double f(int x) {
      for(int i = 0; i < MX; i++)
                  for(int j = 0; j < MX; j++)
                        for(int k = 0; k < MX; k++)
                              dp[i][j][k] = 1e9;
       
      dp[0][0][0] = 0;
      for(int i = 0; i < N; i++) {
            for(int j = 0; j <= N; j++) { // votes
                  for(int k = 0; k <= N; k++) { // num of collaborator
                        if(dp[i][j][k] == 1e9) continue;
 
                        // skip
                        dp[i + 1][j][k] = min(dp[i + 1][j][k], dp[i][j][k]);

                        // ambil vote
                        dp[i + 1][j + 1][k] = min(dp[i + 1][j + 1][k], dp[i][j][k] + (double) v[i].second / (x + 1));
                        
                        // ambil collaborator
                        if(v[i].first != 1e9) 
                              dp[i + 1][j + 1][k + 1] = min(dp[i + 1][j + 1][k + 1], dp[i][j][k] + (double) v[i].first / (k + 1));
                  }
            }
      }

      return dp[N][K][x];
}
 
int main() {
      cin.tie(0); ios_base::sync_with_stdio(0);

      cin >> N >> K;
 
      int tot = 0;
      for(int i = 1; i <= N; i++) {
            cin >> a[i] >> b[i];
            if(b[i] != -1) tot++;
            else b[i] = 1e9;
            v.push_back({b[i], a[i]});
      }
 
      sort(v.begin(), v.end());

      double ans = 1e9;
      int l = 0, r = min(K, tot);

      while(r - l > 1) {
            int mid = (l + r) >> 1;
            if(f(mid) > f(mid + 1)) 
                  l = mid;
            else 
                  r = mid;
      } 

      cout << fixed << setprecision(15) << min(f(l), f(l + 1)) << '\n';
 
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:56:14: warning: unused variable 'ans' [-Wunused-variable]
   56 |       double ans = 1e9;
      |              ^~~

• 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