217. Contains Duplicate

问题描述

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.

思路

先排序，然后两两对比，有相同的返回True，否则False

    def containsDuplicate(self, nums):
        """
        :type nums: List[int]
        :rtype: bool
        """
        if len(nums) ==0: return False
        nums.sort()
        tmp = nums[0]
        for i in range (1, len(nums)):
            if nums[i] == tmp:
                return True
            tmp = nums[i]
        return False

别人的骚操作

def containsDuplicate(self, nums):
        """
        :type nums: List[int]
        :rtype: bool
        """
        num_set = set(nums)
        if len(nums) == len(num_set):
            return False
        return True