Submission #916080

#	Time	Username	Problem	Language	Result	Execution time	Memory
916080		yeediot	Let's Win the Election (JOI22_ho_t3)	C++14	100 / 100	359 ms	4996 KiB

Main

#include<bits/stdc++.h>
using namespace std;
#define int long long 
#define pb push_back
#define pii pair<int,int>
#define F first
#define S second
#define all(X) X.begin(),X.end()
#define chmax(a,b) a=max(a,b)
#define chmin(a,b) a=min(a,b)
#ifdef local
void setio(){freopen("/Users/iantsai/Library/Mobile Documents/com~apple~CloudDocs/cpp/Empty.md","r",stdin);}
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
void setio(){}
#define debug(x...)
#endif
bool cmp(pii a,pii b){
    if(a.S!=b.S)return a.S<b.S;
    return a.F<b.F;
}
const int inf=2e12;
signed main(){
    cout<<fixed<<setprecision(10);
    ios::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    setio();
    int n,k;
    cin>>n>>k;
    vector<pii>vec;
    vec.pb({0,0});
    for(int i=0;i<n;i++){
        int a,b;
        cin>>a>>b;
        vec.pb({a,b});
        if(b==-1){
            vec[i+1].S=inf;
        }
    }
    sort(all(vec),cmp);
    vector<vector<int>>suf(n+2,vector<int>(k+2,0));
    for(int i=1;i<=k;i++){
        multiset<int>st;
        int sum=0;
        for(int j=n;j>=1;j--){
            st.insert(vec[j].F);
            sum+=vec[j].F;
            if((int)(st.size())>i){
                sum-=*prev(st.end());
                st.erase(prev(st.end()));
            }
            if((int)(st.size())==i){
                suf[j][i]=sum;
            }
        }
    }
    double ans=inf;
    for(int p=0;p<=k;p++){
        vector<vector<double>>dp(n+1,vector<double>(p+1,inf));
        dp[0][0]=0;
        for(int i=0;i<=k;i++){
            for(int j=0;j<=p;j++){
                if(j and i)dp[i][j]=dp[i-1][j-1]+(double)vec[i].S/j;
                if(i)dp[i][j]=min(dp[i][j],dp[i-1][j]+(double)vec[i].F/(p+1));
                //cout<<i<<' '<<j<<' '<<dp[i][j]<<' '<<vec[i].F<<'\n';
                if(j==p){
                    chmin(ans,dp[i][j]+(double)suf[i+1][k-i]/(p+1));
                    //cout<<i<<' '<<j<<' '<<ans<<' '<<dp[i][j]<<'\n';
                }
            }
        }
        //cout<<ans<<'\n';
    }
    cout<<ans<<'\n';
}

• 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