Contains Duplicate

Author: Shikha-code36

Arrays/217-Contains-duplicate.py

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+'''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
+def containsDuplicate(nums):
+    for i in range(len(nums)):
+        for j in range(i+1, len(nums)):
+            if nums[i] == nums[j]:
+                return True
+            return False
+
+# T:O(N^2)
+# S:O(1)
+
+
+# Solution2
+def containsDuplicate(nums):
+    hashset = set()
+
+    for i in len(nums):
+        if nums[i] in hashset:
+            return True
+        hashset.add(nums[i])
+    return False
+
+# T: O(N)
+# S: O(N)
+
+# Solution3
+def containsDuplicate(nums):
+    nums.sort()
+
+    for i in len(1, nums):
+        if nums[i] == nums[i-1]:
+            return True
+        return False
+
+# T: O(nlogN)
+# S: O(1)