Submission #471107

#	Time	Username	Problem	Language	Result	Execution time	Memory
471107		Killer2501	Sure Bet (CEOI17_sure)	C++14	100 / 100	167 ms	4420 KiB

sure

#include<bits/stdc++.h>

using namespace std;
 
const int N=1e5+5;
int n;
double a[N],b[N];
long long s[N], mod = 1e9;
 
bool check(long long lim)
{
    long long cur=0;
    for(int i=1;i<=n;i++)
    {
        cur+=a[i];
        long long mx=(cur-lim)/mod-i;
        if(mx<0) continue;
        mx=min(mx,1ll*n);
        if(s[mx]-mod*i>=lim) return true;
    }
    return false;
}
 
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cin>>n;
    for(int i=1;i<=n;i++)
    {
        cin>>a[i]>>b[i];
        a[i]*=mod;
        b[i]*=mod;
    }
    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=1;i<=n;i++) s[i]=max(s[i-1],s[i-1]+(long long)b[i]-mod);
    long long l=1,r= mod * mod,res=0;
    while(l<=r)
    {
        long long mid=(l+r)/2;
        if(check(mid))
        {
            res=mid;
            l=mid+1;
        }
        else r=mid-1;
    }
    cout<<fixed<<setprecision(4)<<1.0*res/mod;
}

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