import 'dart:math';

class NumberTool {

  /// 生成随机数
  /// @allNum: 随机数的和
  /// @num: 随机数的数量
  List<int> randomNum(int allNum, {int num = 10}) {
    Random random = Random();

    // 基础数字 最小值
    int base = allNum ~/ 1.5 ~/ num;
    List<int> numbers = List.generate(num, (index) => base);


    for (int i = 0; i < num - 1; i++) {
      int randomNumber = random.nextInt(base); // 生成0到base之间的随机整数
      numbers[i] += randomNumber;
    }

    int sum = numbers.reduce((a, b) => a + b) ;
    int lastNumber = allNum - sum;

    // 将最后一个数 /2  再/数量 取整数
    base = (lastNumber / 2) ~/ (num);
    for (int i = 0; i < num - 1; i++) {
      numbers[i] += base;
    }

    sum = numbers.reduce((a, b) => a + b);
    lastNumber = allNum - sum;

    // 将最后一个数 切一半 随机加到数组中
    base = lastNumber ~/ 2;
    numbers[ random.nextInt(num - 1)] = base;
    sum = numbers.reduce((a, b) => a + b);
    lastNumber = allNum - sum;

    numbers.add(lastNumber);

    // 打乱顺序
    numbers.shuffle();

    return numbers;
  }

}