面试真题设计一个抢红包算法，单个红包最大不能超过总金额的90%

Posted 2022-07-28 Cry丶

题干：

总金额 double total = 100D;    
总人数 int num = 10;
返回一个List<Double>

参考代码：

public class RedWars 

    public static List<Double> list = new ArrayList<>(10);
    public static double remain;
    public static double used;

    public static List<Double> solution(double total, int num) 
        if (num < 2) 
            list.add(remain);
            return list;
        
        Random random = new Random();
        double bound = random.nextInt(91) / 100.0;
        remain = total;
        used = remain * bound;
        BigDecimal b0 = new BigDecimal(used);
        used = b0.setScale(2, BigDecimal.ROUND_HALF_UP).doubleValue();
        Math.round(used);
        list.add(used);
        remain = remain - used;
        BigDecimal b1 = new BigDecimal(remain);
        remain = b1.setScale(2, BigDecimal.ROUND_HALF_UP).doubleValue();
        return solution(remain, --num);

    

    public static void main(String[] args) 
        double total = 100;
        int num = 10;
        List<Double> solution = solution(total, num);
        System.out.println(solution);
    

输出：

[33.0, 43.55, 7.03, 13.96, 1.21, 0.98, 0.02, 0.18, 0.0, 0.07]