268. Missing Number

https://leetcode.com/problems/missing-number/description/

解题思路：

1. 先排序，然后判断nums[i] == i

代码：
class Solution {
public int missingNumber(int[] nums) {

    if(nums == null) return 0;
    Arrays.sort(nums);
    int len = nums.length;
    for(int i = 0; i < len; i++){
        if(nums[i] != i)
            return i;
    }
    return len;
}

}