[kayden] Week 13 Solutions

house-robber/kayden.py

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+class Solution:
+    # 시간복잡도: O(N)
+    # 공간복잡도: O(1)
+    def rob(self, nums: List[int]) -> int:
+        one, two = 0, 0
+
+        for num in nums:
+            temp = max(two+num, one)
+            two, one = one, temp
+
+        return one

lowest-common-ancestor-of-a-binary-search-tree/kayden.py

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+class Solution:
+    # 시간복잡도: O(N)
+    # 공간복잡도: O(1)
+    def lowestCommonAncestor(self, root: 'TreeNode', p: 'TreeNode', q: 'TreeNode') -> 'TreeNode':
+        def find(node):
+            if not node:
+                return None
+
+            left = find(node.left)
+            right = find(node.right)
+
+            if node == p or node == q:
+                return node
+
+            if left and right:
+                return node
+
+            return left or right
+
+        return find(root)

meeting-rooms/kayden.py

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+class Solution:
+    # 시간복잡도: O(NlogN)
+    # 공간복잡도: O(1)
+    def can_attend_meetings(self, intervals: List[Interval]) -> bool:
+        intervals.sort()
+
+        prev = 0
+        for start, end in intervals:
+            if end < prev:
+                return False
+
+            prev = end
+
+        return True