Java 代码

import java.util.Scanner;

public class Main
{
    public static void main(String[] args)
    {
        Scanner cin = new Scanner(System.in);

        double n = cin.nextDouble();

        int[] r = {0, 25, 50, 75, 100};

        if ( n < r[0] || n > r [4])
            System.out.println ("Fora de intervalo");
        else
        {
            for (int i = 0; i < r.length -1; i ++ )
            {
                if ( n >= r[i] && n <= r[i+1])
                {
                    if (i == 0)
                        System.out.println ("Intervalo [" + r[i] + "," + r[i+1] + "]");
                    else
                        System.out.println ("Intervalo (" + r[i] + "," + r[i+1] + "]");
                    break;
                }
            }
        }

    }
}