Submission #425653

#	Time	Username	Problem	Language	Result	Execution time	Memory
425653		oleh1421	Sure Bet (CEOI17_sure)	C++17	100 / 100	123 ms	5264 KiB

sure

#include<bits/stdc++.h>
typedef long long ll;
using namespace std;
const int N=100010;
const ll mod=1000000007;
const ll inf=1e15;
double a[N],b[N];
int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    int n;cin>>n;
    vector<double>v;
    for (int i=1;i<=n;i++) {
        cin>>a[i]>>b[i];
        v.push_back(a[i]);
        v.push_back(b[i]);
    }
    sort(a+1,a+n+1);
    sort(b+1,b+n+1);
    reverse(a+1,a+n+1);
    reverse(b+1,b+n+1);
    for (int i=2;i<=n;i++) a[i]+=a[i-1];
    for (int i=2;i<=n;i++) b[i]+=b[i-1];
    double res=0.0;
    for (int len=1;len<=2*n;len++){
        int l=max(0,len-n);
        int r=min(n,len);
        int pos=l;
        for (int i=20;i>=0;i--){
            if (pos+(1<<i)<=r && a[pos+(1<<i)]<=b[len-pos-(1<<i)]) pos+=(1<<i);
        }
        for (int i=pos;i<=min(r,pos+1);i++){
            int j=len-i;
            res=max(res,min(a[i]-len,b[j]-len));
        }
    }
    cout<<setprecision(4)<<fixed<<res<<endl;
    return 0;
}

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