Submission #979720

#	Time	Username	Problem	Language	Result	Execution time	Memory
979720		12345678	Mobile (BOI12_mobile)	C++17	100 / 100	552 ms	35456 KiB

mobile

#include <bits/stdc++.h>

using namespace std;

const int nx=1e6+5;

int n, L;
pair<double, double> p[nx];

int main()
{
    cin.tie(NULL)->sync_with_stdio(false);
    cin>>n>>L;
    for (int i=1; i<=n; i++) cin>>p[i].first>>p[i].second;
    double l=0, r=2e9;
    while (r-l>1e-4)
    {
        double md=(l+r)/2, mx=0;
        for (int i=1; i<=n; i++)
        {
            double x=md*md-p[i].second*p[i].second;
            if (x<0) continue;
            x=sqrt(x);
            if (p[i].first-x<=mx) mx=max(mx, p[i].first+x);
        }
        if (mx>=L) r=md;
        else l=md;
    }
    cout<<fixed<<setprecision(4)<<l;
}

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• Subtask 21: 5 / 5