Submission #960262

#	Time	Username	Problem	Language	Result	Execution time	Memory
960262		irmuun	Sure Bet (CEOI17_sure)	C++17	100 / 100	75 ms	5200 KiB

sure

#include<bits/stdc++.h>
 
using namespace std;
 
#define ll long long
#define pb push_back
#define ff first
#define ss second
#define all(s) s.begin(),s.end()
#define rall(s) s.rbegin(),s.rend()
 
int main(){
    ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
    int n;
    cin>>n;
    vector<double>a(n),b(n);
    for(int i=0;i<n;i++){
        cin>>a[i]>>b[i];
    }
    sort(rall(a));
    sort(rall(b));
    vector<double>sa(n+1),sb(n+1);
    sa[0]=0;
    sb[0]=0;
    for(int i=0;i<n;i++){
        sa[i+1]=sa[i]+a[i];
        sb[i+1]=sb[i]+b[i];
    }
    double ans=0;
    for(int i=1;i<=n;i++){
        int l=0,r=i;
        while(l<r){
            int mid=(l+r+1)/2;
            if(sa[mid]<=sb[i-mid]){
                l=mid;
            }
            else{
                r=mid-1;
            }
        }
        ans=max(ans,sa[l]-i);
        if(l<i){
            ans=max(ans,sb[i-l-1]-i);
        }
    }
    for(int i=n+1;i<=2*n;i++){
        int l=i-n,r=n;
        if(sa[l]<=sb[n]){
            while(l<r){
                int mid=(l+r+1)/2;
                if(sa[mid]<=sb[i-mid]){
                    l=mid;
                }
                else{
                    r=mid-1;
                }
            }
            ans=max(ans,sa[l]-i);
            if(l<n){
                ans=max(ans,sb[i-l-1]-i);
            }
        }
        else{
            while(l<r){
                int mid=(l+r+1)/2;
                if(sb[mid]<=sa[i-mid]){
                    l=mid;
                }
                else{
                    r=mid-1;
                }
            }
            ans=max(ans,sb[l]-i);
            if(l<n){
                ans=max(ans,sa[i-l-1]-i);
            }
        }
    }
    printf("%.4f",ans);
}

• Subtask 1: 20 / 20
• Subtask 2: 40 / 40
• Subtask 3: 40 / 40