nyoj-1092-数字分隔（二）

java大法好啊

思路:单独拿出整数部分分隔

题目链接

 import java.math.BigDecimal;
 import java.util.Scanner;

 public class Main{

     public static void main(String[] args) {
         Scanner cin = new Scanner(System.in);
         while (cin.hasNext()) {
             BigDecimal num = new BigDecimal("0");
             num = cin.nextBigDecimal();

             // 判断负数
             boolean flag = true;
             if (num.compareTo(BigDecimal.valueOf(0)) < 0) {
                 flag = false;
                 num = num.abs();
             }
             num = num.setScale(2, BigDecimal.ROUND_HALF_UP);
             // 保留小数部分
             String str = num.toString();
             String tail = str.substring(str.indexOf("."), str.length());

             // 保留头部
             StringBuffer head = new StringBuffer(str.substring(0, str.indexOf(".")));

             int j = 0;
             for (int i = head.length() - 1; i > 0; i--) {
                 if (head.charAt(i) != ',' && ++j == 3) {
                     head.insert(i, ",");
                     j = 0;
                 }
             }
             if (flag == true) {
                 System.out.print(head + tail + "\n");
             } else {
                 System.out.print("(" + head + tail + ")"  + "\n");
             }
         }

     }

 }