1. 题目

读题

HJ105 记负均正II 

考查点

有个知识点：不确定大小的数组怎么办？Java中三种常用的方法

2. 解法

思路

代码逻辑

具体实现

public class HJ105 {

    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        List<Integer> list = new ArrayList<>();
        while (sc.hasNext()) {
            list.add(Integer.valueOf(sc.nextLine()));
        }
        sc.close();
        count((Integer[]) list.toArray(new Integer[0]));

    }

    public static void count(Integer[] nums) {

        int negCnt = 0;
        int unNegCnt = 0;
        int unNegSum = 0;
        for (int num : nums) {
            if (num < 0) {
                negCnt++;
            } else {
                unNegCnt++;
                unNegSum += num;
            }
        }

        System.out.println(negCnt);
        String unNegAvg;
        if (unNegCnt == 0) {
            unNegAvg = "0.0";
        } else {
            unNegAvg = new DecimalFormat("#0.0").format((double) unNegSum / unNegCnt);
        }
        System.out.println(unNegAvg);

    }
}

3. 总结