5 not solved

Author: devyulbae

contains-duplicate/devyulbae.py

@@ -1,5 +1,5 @@
 """
-Blind75 - 3. Contains Duplicate
+Blind75 - 1. Contains Duplicate
 https://leetcode.com/problems/contains-duplicate/
 
 Counter를 사용한 풀이

house-robber/devyulbae.py

@@ -0,0 +1,26 @@
+"""
+blind75 - House Robber
+LeetCode Problem: https://leetcode.com/problems/house-robber/
+
+재귀
+F(x) = F(x+1), F(x+2) + nums[x] 중 큰 값을 계속 선택하면 된다
+-> 재귀를 2번씩 호출하기 때문에 시간복잡도는 O(2^n)으로 Time Limit Exceeded 발생
+다음 주차 때 다시 풀어보자.
+dp로도 될 거 같다
+"""
+
+from typing import List
+
+class Solution:
+    def rob(self, nums: List[int]) -> int:
+        if not nums:
+            return 0
+        
+        def dfs(s):
+            if s >= len(nums):
+                return 0
+            return max(dfs(s+1), nums[s] + dfs(s+2))
+        
+        return dfs(0)
+        
+        

longest-consecutive-sequence/devyulbae.py

@@ -3,9 +3,28 @@
 https://leetcode.com/problems/longest-consecutive-sequence/
 
 조건 : O(n) 시간복잡도
+1. 시작점이면 초기화
+2. 아니면 cnt++
+3. 끊기면 max 갱신
 """
-
+from typing import List
 
 class Solution:
     def longestConsecutive(self, nums: List[int]) -> int:
-        
+        if len(nums) == 0:
+            return 0
+        nums.sort()
+        length = 1
+        max_length = 0
+        for i in range(len(nums)-1):
+            if nums[i+1] == nums[i]:
+                continue
+            elif nums[i+1] == nums[i] + 1:
+                length += 1
+            else:
+                max_length = max(max_length, length)
+                length = 1
+        
+        max_length = max(max_length, length)
+        return max_length
+