Input: [1,2,3,1]
Output: true
Input: [1,2,3,4]
Output: false
return True if contains duplicate
- c0, it’s O(n) to make a set from a list. Set result is out of order!
return True if len(nums) != len(set(nums)) else False
- c1
class Solution:
def containsDuplicate(self, nums: List[int]) -> bool:
if not len(nums):
return False
nums.sort()
left = nums[0]
for i in nums[1:]:
if i == left:
return True
left = i
return False