nyoj 155 求高精度冪

http://acm.nyist.net/JudgeOnline/problem.php?pid=155

注意去除前置0，去除和小數最後面的0.要用到stripTrailingZeros函數，另外要注意，高精度浮點數BigDecimal類計算輸出自動按照科學計數法來，要用toPlainString函數恢複最初狀態。

import java.math.BigDecimal;import java.util.Scanner;public class Main {public static void main(String...args){while(cin.hasNext()){a = cin.nextBigDecimal();int powNum = cin.nextInt();res = a.pow(powNum);if(a.compareTo(BigDecimal.ONE) >= 0)System.out.println(res.stripTrailingZeros().toPlainString());else{String result = res.stripTrailingZeros().toPlainString();for(int i = 1; i < result.length(); i++)System.out.print(result.charAt(i));System.out.println();}}}public static BigDecimal a, res;static Scanner cin = new Scanner(System.in);}