代码是很久以前写的（现在看不懂了），但没过，改了一下，测了很多数据好像还可以，就是WA

import java.util.*;
import java.math.*;

public class Main
{
    public static void main(String args[])
    {
        final BigInteger inf = BigInteger.TEN.pow(1000);
        BigInteger g[], b[];
        int d, a[], p[], q[], i, j, a02;
        double d2;
        Scanner cin = new Scanner(System.in);
        try
        {
            a = new int[50000];
            p = new int[50000];
            q = new int[50000];
            p[0] = 0;
            q[0] = 1;
            for (;;)
            {
                d = cin.nextInt();
                d2 = Math.sqrt(d);
                int dd = (int) (d2+0.000001);
                if (dd * dd == d)
                {
                    System.out.println("No solution!");
                    continue;
                }
                a02 = (int) ((p[0] + d2) / q[0]) * 2;
                g = new BigInteger[50000];
                b = new BigInteger[50000];
                g[0] = BigInteger.valueOf(0);
                g[1] = BigInteger.valueOf(1);
                b[0] = BigInteger.valueOf(1);
                b[1] = BigInteger.valueOf(0);
                for (i = 0;; ++i)
                {
                    a[i] = (int) ((p[i] + d2) / q[i]);
                    if (a[i] == a02)
                        break;
                    p[i + 1] = a[i] * q[i] - p[i];
                    q[i + 1] = (d - p[i + 1] * p[i + 1]) / q[i];
                    g[i + 2] = g[i + 1].multiply(BigInteger.valueOf(a[i])).add(
                            g[i]);
                    b[i + 2] = b[i + 1].multiply(BigInteger.valueOf(a[i])).add(
                            b[i]);
                }
                if ((i & 1) == 1)
                {
                    int ii = 2 * (i+1);
                    for (; i < ii; ++i)
                    {
                        a[i] = (int) ((p[i] + d2) / q[i]);
                        p[i + 1] = a[i] * q[i] - p[i];
                        g[i + 2] = g[i + 1].multiply(BigInteger.valueOf(a[i]))
                                .add(g[i]);
                        b[i + 2] = b[i + 1].multiply(BigInteger.valueOf(a[i]))
                                .add(b[i]);
                    }
                    if(inf.compareTo(g[i-1])>0 && inf.compareTo(b[i-1])>0)
                        System.out.println(g[i - 1].toString() + " "
                                + b[i - 1].toString());
                    else
                        System.out.println("No solution!");
                }
                else
                    if(inf.compareTo(g[i+1])>0 && inf.compareTo(b[i+1])>0)
                        System.out.println(g[i + 1].toString() + " "
                                + b[i + 1].toString());
                    else
                        System.out.println("No solution!");
            }
        } catch (Exception e)
        {
        }
    }
}

• 27237237 --- no solution (3136) frkstyc 2005-07-05 18:28:32
  • 过了。谢谢，误删了一条语句。 (0) lookus 2005-07-05 18:40:12
  • 这个数不是平方数，不过最小正解超长了 (0) frkstyc 2005-07-05 18:41:18