# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
937998 | vjudge1 | Let's Win the Election (JOI22_ho_t3) | C++17 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
using namespace std;
typedef long double ld;
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
int N, K; cin >> N >> K;
vector<pair<ld, ld>> v(N);
bool special = true;
for(int i = 0; i < N; i++){
cin >> v[i].second >> v[i].first;
if(v[i].first == -1) v[i].first = 1e9;
else if(v[i].first != v[i].second) special = false;
}
sort(v.begin(), v.end());
ld ans = 7e18;
if(special){
for(int collaborators = 0; collaborators < K; collaborators++){
ld cost = 0;
ld hv = 1;
for(int i = 0; i < collaborators; i++){
cost += v[i].first / hv;
hv++;
}
vector<ld> a;
for(int i = collaborators; i < N; i++){
a.push_back(v[i].second);
}
sort(a.begin(), a.end());
for(int i = 0; i < K - collaborators; i++){
cost += a[i] / hv;
}
ans = min(ans, cost);
}
}else if(K == N){
for(ld collaborators = 0; collaborators < K; collaborators++){
vector<ld> dp(collaborators + 1, 1e18);
dp[0] = 0;
for(int i = 0; i < N; i++){
for(ld j = collaborators; j >= 0; j--){
if(j != collaborators) dp[j+1] = min(dp[j+1], dp[j] + v[i].first / (j+1.0));
dp[j] += v[i].second / (collaborators+1.0);
}
}
ans = min(ans, dp[collaborators]);
}
}else{
if(K == N) continue;
for(ld collaborators = 0; collaborators < K; collaborators++){
vector<vector<ld>> dp(K+1, vector<ld>(collaborators + 1, 1e18));
dp[0][0] = 0;
for(int i = 0; i < N; i++){
for(int elem = K - 1; elem >= 0; elem--){
for(ld j = collaborators; j >= 0; j--){
if(j != collaborators) dp[elem+1][j+1] = min(dp[elem+1][j+1], dp[elem][j] + v[i].first / (j+1.0));
dp[elem+1][j] = min(dp[elem+1][j], dp[elem][j] + v[i].second / (collaborators+1.0));
}
}
}
ans = min(ans, dp[K][collaborators]);
}
}
cout << fixed << setprecision(8) << ans << "\n";
}