Submission #998504

#	Time	Username	Problem	Language	Result	Execution time	Memory
998504		sushikid	Mobile (BOI12_mobile)	Java	90 / 100	1050 ms	100384 KiB

mobile

import java.util.*;
import java.io.*;

public class mobile {
    private static double[][] info;
    private static int l;

    private static boolean check(double rad){
        double max = 0;

        for (int i = 0; i < info.length; i++) {
            double[] intersect = intersect(info[i], rad);
            if(intersect[0] <= max){
                max = Math.max(max, intersect[1]);
            }
        }
        return max >= l;
    }
    private static double[] intersect(double[] point, double rad){
        double change = Math.sqrt(rad * rad - point[1] * point[1]);
        return new double[]{point[0] - change, point[0] + change};
    }
    public static void main(String[] args) throws IOException{
        BufferedReader r = new BufferedReader(new InputStreamReader(System.in));
        PrintWriter pw = new PrintWriter(System.out);

        StringTokenizer st = new StringTokenizer(r.readLine());
        int n = Integer.parseInt(st.nextToken()); l = Integer.parseInt(st.nextToken());

        info = new double[n][2];

        for (int i = 0; i < n; i++) {
            st = new StringTokenizer(r.readLine());
            info[i][0] = Integer.parseInt(st.nextToken()); info[i][1] = Integer.parseInt(st.nextToken());
        }

        double left = 0; double right = l;
        for (int i = 0; i < 100; i++) {
            double mid = left + (right - left)/2;
            if(check(mid)){
                right = mid;
            }
            else{
                left = mid;
            }
        }
        pw.println(left);
        pw.close();
    }
}

• 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
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• Subtask 10: 5 / 5
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• Subtask 12: 5 / 5
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• Subtask 14: 5 / 5
• Subtask 15: 5 / 5
• Subtask 16: 5 / 5
• Subtask 17: 5 / 5
• Subtask 18: 5 / 5
• Subtask 19: 0 / 5
• Subtask 20: 5 / 5
• Subtask 21: 0 / 5