leetcode 41:First Missing Positive

41.py

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

if __name__ == '__main__':
    sol = Solution()
    x = [10, 11, 12, 0, 0, 0]
    y = [1, 2, 0]
    print(sol.firstMissingPositive(y))