[jeldo3] Week1

contains-duplicate/jeldo.py

@@ -0,0 +1,4 @@
+class Solution:
+    # O(n)
+    def containsDuplicate(self, nums: list[int]) -> bool:
+        return len(nums) != len(set(nums))  # O(n)

house-robber/jeldo.py

@@ -0,0 +1,9 @@
+class Solution:
+    # O(n)
+    def rob(self, nums: list[int]) -> int:
+        if len(nums) <= 2:
+            return max(nums)
+        nums[2] += nums[0]
+        for i in range(3, len(nums)):
+            nums[i] += max(nums[i-3], nums[i-2])
+        return max(nums[-1], nums[-2])

longest-consecutive-sequence/jeldo.py

@@ -0,0 +1,13 @@
+class Solution:
+    # O(n)
+    def longestConsecutive(self, nums: list[int]) -> int:
+        max_length = 0
+        nums_set = set(nums)
+        for n in nums_set:
+            if n - 1 not in nums_set:
+                length = 0
+                while n + length in nums_set:
+                    length += 1
+                    max_length = max(max_length, length)
+
+        return max_length

top-k-frequent-elements/jeldo.py

@@ -0,0 +1,9 @@
+from collections import Counter
+import heapq
+
+
+class Solution:
+    # O(nlogn)
+    def topKFrequent(self, nums: list[int], k: int) -> list[int]:
+        ls = [(key, value) for key, value in Counter(nums).items()]  # O(n)
+        return [key for _, key in heapq.nlargest(n=k, iterable=ls)]  # O(nlogn)

valid-palindrome/jeldo.py

@@ -0,0 +1,5 @@
+class Solution:
+    # O(n)
+    def isPalindrome(self, s: str) -> bool:
+        s = ''.join(ch.lower() for ch in s if ch.isalnum())  # O(n)
+        return s == s[::-1]  # O(n)