217-Contains-duplicate.py

'''Leetcode - https://leetcode.com/problems/contains-duplicate/'''
'''
Given an integer array nums, return true if any value appears at least twice in the array, and return false if every element is distinct.

Input: nums = [1,2,3,1]
Output: true
'''

# Solution1
defcontainsDuplicate(nums):
foriinrange(len(nums)):
forjinrange(i+1, len(nums)):
ifnums[i] ==nums[j]:
returnTrue
returnFalse

# T:O(N^2)
# S:O(1)


# Solution2
defcontainsDuplicate(nums):
hashset=set()

foriinlen(nums):
ifnums[i] inhashset:
returnTrue
hashset.add(nums[i])
returnFalse

# T: O(N)
# S: O(N)

# Solution3
defcontainsDuplicate(nums):
nums.sort()

foriinlen(1, nums):
ifnums[i] ==nums[i-1]:
returnTrue
returnFalse

# T: O(nlogN)
# S: O(1)