java 根据最小值和最大值以及数组之和来生成对应的数组

java 复制代码
  /**
     * 生成对应的数组
     *
     * @param totalAmount 需要生成数组的总金额
     * @param num         需要生成数字的个数
     * @param min         最小的金额
     * @param max         最大的金额
     * @return 生成的数组
     * @throws IllegalArgumentException 如果参数无效
     */
    public static int[] lotteryArray(int totalAmount, int num, int min, int max) {
        if (num <= 0 || min < 0 || max <= min || totalAmount < num * min) {
            throw new YshopException("lotteryArray的参数无效");
        }

        int[] rewards = new int[num];
        Random random = new Random();
        int remainingAmount = totalAmount;

        for (int i = 0; i < num - 1; i++) {
            // 确保生成的随机数在min和max之间，并且剩余的总金额足够分配给剩余的所有奖励
            int remainingRewards = num - i;
            int maxPossibleReward = Math.min(remainingAmount / remainingRewards, max);
            int minPossibleReward = Math.max(min, remainingAmount - (remainingRewards - 1) * max);


            // 生成随机奖励
            int reward = minPossibleReward + random.nextInt(maxPossibleReward - minPossibleReward + 1);
//
//            if (reward>max){
//                System.out.println("reward大于max:"+reward);
//            }
//
//            if (reward<min){
//                System.out.println("reward小于min:"+reward);
//            }


            rewards[i] = reward;
            remainingAmount -= reward;
        }

        // 最后一次迭代：直接设置剩余金额，确保总和正确
        rewards[num - 1] = remainingAmount;


        if (rewards[num - 1] < min || rewards[num - 1] > max) {
            // System.out.println("最后一位数递归:"+rewards[num - 1]);
            // 如果最后一个奖励小于min，这通常意味着输入参数不合理，可以递归重新计算
            return lotteryArray(totalAmount, num, min, max);
        }

        // 确保最后生成的总金额是预期的totalAmount
        if (Arrays.stream(rewards).sum() != totalAmount) {
            // 如果总和不对，重新计算整个数组
            // System.out.println("总数不对递归");
            return lotteryArray(totalAmount, num, min, max);
        }

        // System.out.println("rewards:"+ Arrays.toString(rewards) +"---------");

        return rewards;
    }