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");
            }
        }

    }

}