Submission #938947

#	Time	Username	Problem	Language	Result	Execution time	Memory
938947		Pacybwoah	Let's Win the Election (JOI22_ho_t3)	C++17	100 / 100	43 ms	4472 KiB

Main

#include<iostream>
#include<vector>
#include<iomanip>
#include<utility>
#include<algorithm>
using namespace std;
typedef long double ld;
vector<pair<ld,ld>> vec;
int n,k;
ld solve(int m){
    vector<vector<ld>> dp(n+1,vector<ld>(k-m+1,1e9+7));
    dp[1][0]=(m>0?vec[1].first:0);
    if(k-m>0) dp[1][1]=vec[1].second/ld(m+1);
    for(int i=2;i<=n;i++){
        for(int j=0;j<=min(k-m,i);j++){
            if(i!=j) dp[i][j]=min(dp[i][j],dp[i-1][j]+(i-j>m?0:vec[i].first/(long double)(i-j)));
            if(j>0) dp[i][j]=min(dp[i][j],dp[i-1][j-1]+vec[i].second/(long double)(m+1));
        }
    }
    /*for(int i=1;i<=n;i++){
        for(int j=0;j<=k-m;j++) if(m==2) cout<<dp[i][j]<<" ";
        cout<<"\n";
    }*/
    return dp[n][k-m];
}
int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cin>>n>>k;
    vec.resize(n+1);
    for(int i=1;i<=n;i++) cin>>vec[i].second>>vec[i].first;
    for(int i=1;i<=n;i++) if(vec[i].first==-1) vec[i].first=1e9;
    sort(next(vec.begin()),vec.end());
    //for(int i=1;i<=n;i++) cout<<vec[i].first<<' '<<vec[i].second<<"\n";
    int l=0,r=k;
    ld ans=1e9+7;
    while(l<r){
        int mid=(l+r)>>1;
        ld a=solve(max(mid,0)),b=solve(min(mid+1,r));
        ans=min(ans,min(a,b));
        if(a>b) l=min(mid+1,r);
        else r=(max(mid,0));
    }
    //for(int i=0;i<=k;i++) ans=min(ans,solve(i));
    cout<<fixed<<setprecision(12)<<ans;
}

• 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