3352523_re.java

北大大牛代码 1240道题的原代码 超级权威

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

public class Main
{
	public static void main(String [] args)
	{
		new Main().run();
	}

	public void run()
	{
		Scanner in = new Scanner (System.in);
		int t, a, b;

		while (in.hasNext())
		{
			t = in.nextInt();
			b = in.nextInt();
			a = in.nextInt();
			System.out.print("("+t+"^"+b+"-1)/("+t+"^"+a+"-1) ");
			if (t == 1 || b % a != 0)
			{
				System.out.println("is not an integer with less than 100 digits.");
				continue;
			}
			double len = (double)(b-a) * Math.log10((double)t) + 1.0;
			if (len >= 100.0)
			{
				System.out.println("is not an integer with less than 100 digits.");
				continue;
			}
			int n = b / a;
			BigInteger base = BigInteger.valueOf(t).pow(a);
			BigInteger tmp = BigInteger.ONE;
			BigInteger ans = BigInteger.ZERO;
			for (int i = 0; i < n; i++)
			{
				ans = ans.add(tmp);
				tmp = tmp.multiply(base);
			}
			System.out.println(ans);
		}
	}
}