POJ 1131 Octal Fractions——高精度

package main;import java.io.*;import java.util.*;import java.math.*;public class Main {public static void main(String[] args) {Scanner in = new Scanner(new BufferedInputStream(System.in));String s;BigDecimal one = new BigDecimal(1);BigDecimal eight = new BigDecimal(8);while (in.hasNext()) {s = in.nextLine();BigDecimal ode = one.divide(eight);BigDecimal ans = new BigDecimal(0);for (int i = 2; i < s.length(); i++) {ans = ans.add(ode.multiply(new BigDecimal(s.charAt(i) - '0')));ode = ode.divide(eight);}System.out.println(s + " [8] = " + ans.toString()  + " [10]");}in.close();}}