Submission #1247326

#	Time	Username	Problem	Language	Result	Execution time	Memory
1247326		chikien2009	Mobile (BOI12_mobile)	C++20	100 / 100	629 ms	16092 KiB

mobile

#include <bits/stdc++.h>

using namespace std;

void setup()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
}

int n, m;
double res = 0, l = 0, r = 1e9 + 5e8, mid, len, lb, rb, x[1000000], y[1000000];

int main()
{
    setup();

    cin >> n >> m;
    for (int i = 0; i < n; ++i)
    {
        cin >> x[i] >> y[i];
    }
    for (int i = 0; i < 50; ++i)
    {
        mid = (l + r) / 2;
        len = 0;
        for (int j = 0; j < n; ++j)
        {
            if (y[j] <= mid)
            {
                lb = x[j] - sqrt(mid * mid - y[j] * y[j]);
                rb = x[j] + sqrt(mid * mid - y[j] * y[j]);
                if (lb <= len)
                {
                    len = max(len, rb);
                }
            }
        }
        if (m <= len)
        {
            res = mid;
            r = mid - 1;
        }
        else
        {
            l = mid + 1;
        }
    }
    cout << fixed << setprecision(6) << res;
    return 0;
}

• Subtask 1: 4 / 4
• Subtask 2: 4 / 4
• Subtask 3: 4 / 4
• Subtask 4: 4 / 4
• Subtask 5: 4 / 4
• Subtask 6: 5 / 5
• Subtask 7: 5 / 5
• Subtask 8: 5 / 5
• Subtask 9: 5 / 5
• Subtask 10: 5 / 5
• Subtask 11: 5 / 5
• Subtask 12: 5 / 5
• Subtask 13: 5 / 5
• Subtask 14: 5 / 5
• Subtask 15: 5 / 5
• Subtask 16: 5 / 5
• Subtask 17: 5 / 5
• Subtask 18: 5 / 5
• Subtask 19: 5 / 5
• Subtask 20: 5 / 5
• Subtask 21: 5 / 5