UVA 748 Exponentiation

java解决大数幂。输入r和n，输出r的n次方，除去前后无用的0.

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

public class Main {
	public static void main(String[] args){
		Scanner cin = new Scanner(System.in);
		BigDecimal r, ans;
		String s;
		int n, l, i;
		while(cin.hasNext()){
			r = cin.nextBigDecimal();
			n = cin.nextInt();
			ans = r.pow(n);
			s = ans.toPlainString();
			if(!s.contains("."))System.out.println(s);
			else{
				l = s.length();
				while(s.charAt(l - 1) == '0')l--;
				for(i = 0; i < l; i++)if(s.charAt(i) != '0')break;
				for(; i < l; i++)System.out.print(s.charAt(i));
				System.out.println();
			}
		}
	}
}