LeetCode69|消失的数字

示例 1：
输入：[3,0,1]
输出：2

示例 2：

输入：[9,6,4,2,3,5,7,0,1]
输出：8

 
public class MissingNumberTest {
    public static void main(String[] args) {
        int[] nums = {9, 6, 4, 2, 3, 5, 7, 0, 1};
        int missingNumber = missingNumber(nums);
        System.out.println("missingNumber = " + missingNumber);
    }

    public static int missingNumber(int[] nums) {
        if (nums == null || nums.length == 0) {
            return -1;
        }
        int[] newArray = new int[nums.length + 1];
        for (int num : nums) {
            newArray[num]++;
        }
        for (int i = 0; i < newArray.length; i++) {
            if (newArray[i] == 0) {
                return i;
            }
        }
        return -1;
    }
}