41.md

题目地址

https://leetcode-cn.com/problems/first-missing-positive/

解答

def firstMissingPositive(nums):
    """ 缺失的第一个正整数 """
    if not nums:
        return 1
    set1 = {i for i in range(1, len(nums) + 2)}
    set2 = set(nums)
    set1 -= set2

    return list(set1)[0]