leetcode——41. 缺失的第一个正数

class Solution(object):
    def firstMissingPositive(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        if nums==[]:
            return 1
        for i in nums:
            if i<=0:
                nums.remove(i)
        if nums==[]:
            return 1
        for i in range(1,len(nums)+1):
            if i not in nums:
                return i
        return len(nums)+1