解Pell方程(java)

转载出处： http://blog.youkuaiyun.com/acdreamers/article/details/8529686

题目出处： NEFU682Happiness Hotel

import java.math.BigInteger;    
import java.util.Scanner;    
  
public class Main  
{    
    public static void solve(int n)   
    {    
        BigInteger N, p1, p2, q1, q2, a0, a1, a2, g1, g2, h1, h2,p,q;    
        g1 = q2 = p1 = BigInteger.ZERO;    
        h1 = q1 = p2 = BigInteger.ONE;    
        a0 = a1 = BigInteger.valueOf((int)Math.sqrt(1.0*n));  
        BigInteger ans=a0.multiply(a0);  
        if(ans.equals(BigInteger.valueOf(n)))  
        {  
            System.out.println("\"no solution\""+",");  
            return;  
        }  
        N = BigInteger.valueOf(n);    
        while (true)   
        {    
            g2 = a1.multiply(h1).subtract(g1);       
            h2 = N.subtract(g2.pow(2)).divide(h1);    
            a2 = g2.add(a0).divide(h2);            
            p = a1.multiply(p2).add(p1);             
            q = a1.multiply(q2).add(q1);            
            if (p.pow(2).subtract(N.multiply(q.pow(2))).compareTo(BigInteger.ONE) == 0) break;  
            g1 = g2;h1 = h2;a1 = a2;    
            p1 = p2;p2 = p;    
            q1 = q2;q2 = q;    
        }  
        System.out.println("\""+p+"\""+",");  
    }    
     
    public static void main(String[] args)   
    {    
        int n;
        for(n=1;n<=1000;n++)
        {  
            solve(n);     
        }  
    }    
}    

OJ对JAVA似乎有些不支持，所以还是打表后放到C++程序里提交。