package com.ietree.base.number;

import java.math.BigDecimal;
import java.math.BigInteger;

public class BigIntegerTest {

  public static void main(String[] args) {
    float f1 = 123.01f + 2.01f;
    // 预期输出：125.02，实际输出：125.020004
    System.out.println(f1);
    // 预期输出：125.02，实际输出：125.02000000000001
    System.out.println(123.01 + 2.01);
    System.out.println("===============================");

    // 高精度整数测试
    BigInteger bint1 = new BigInteger("125");
    BigInteger bint2 = new BigInteger("999");
    BigInteger tmp;
    // 相加
    tmp = bint1.add(bint2);
    System.out.println("bint1 + bint2 = " + tmp);
    // 相减
    tmp = bint2.subtract(bint1);
    System.out.println("bint2 - bint1 = " + tmp);
    // 相乘
    tmp = bint1.multiply(bint2);
    System.out.println("bint1 * bint2 = " + tmp);
    // 相除
    tmp = bint2.divide(bint1);
    System.out.println("bint2 / bint1 = " + tmp);
    // 求余数
    tmp = bint2.remainder(bint1);
    System.out.println("bint2 % bint1 = " + tmp);
    // 求次方
    tmp = bint2.pow(2);
    System.out.println("bint2的二次方 = " + tmp);
    System.out.println("======================================");

    // 高精度小数测试
    BigDecimal bd1 = new BigDecimal(123.01);
    BigDecimal bd2 = new BigDecimal(2.01);
    BigDecimal bd;
    // 相加
    bd = bd1.add(bd2);
    System.out.println("bd1 + bd2 = " + bd);
    // 相减
    bd = bd1.subtract(bd2);
    System.out.println("bd2 - bd1 = " + bd);
    // 相乘
    bd = bd1.multiply(bd2);
    System.out.println("bd1 * bd2 = " + bd);
    // 相除
    // bd = bd1.divide(bd2);
    bd = bd1.divide(new BigDecimal(2.0));
    System.out.println("bd1 / 2.0 = " + bd);
    // 求余数
    bd = bd1.remainder(bd2);
    System.out.println("bd2 % bd1 = " + bd);
    // 求次方
    bd = bd1.pow(3);
    System.out.println("bd2的三次方 = " + bd);
    System.out.println("======================================");

    // 四舍五入保留小数位数
    BigDecimal bd3 = new BigDecimal(123.01).setScale(5,5);
    System.out.println("bd3 = " + bd3);
  }
}