217. Contains Duplicate

Given an array of integers, find if the array contains any duplicates.

Your function should return true if any value appears at least twice in the array, and it should return false if every element is distinct.

给一个无序数组，问是否有重复元素，用字典来判断下

class Solution(object):
    def containsDuplicate(self, nums):
        """
        :type nums: List[int]
        :rtype: bool
        """
        d = {}
        for value in nums:
            if value in d:
                return True
            else:
                d[value] = 1
        return False