문제 : https://leetcode.com/problems/is-subsequence/description/ 난이도 : Easy 문자열 s가 t에 포함되어 있는지 찾는 문제다. 어떻게 할까 고민하다가 그냥 찾으면 그 위치부터 자르고, 찾으면 자르고 단순하게 풀기로 했다. (늘 그랬음;;) 풀이1 class Solution: def isSubsequence(self, s: str, t: str) -> bool: answer = False tIdx, sIdx = 0, 0 if len(s) > len(t): return False if len(s) == 0: return True while len(t) > 0 and tIdx > -1: tIdx = t.find(s[sIdx]) if(tIdx > -1): #..
문제 : https://leetcode.com/problems/trim-a-binary-search-tree/ 난이도 : Medium 풀이 class Solution: def trimBST(self, root: Optional[TreeNode], low: int, high: int) -> Optional[TreeNode]: def trim(node) -> Optional[TreeNode]: if node: if node.val > high: return trim(node.left) elif node.val < low: return trim(node.right) else: node.left = trim(node.left) node.right = trim(node.right) return node retur..
문제 : https://leetcode.com/problems/maximum-score-after-splitting-a-string/ 난이도 : Easy 풀이 1 class Solution: def maxScore(self, s: str) -> int: maxScore = 0 for i in range(1, len(s)): cnt = s[:i].count('0') + s[i:].count('1') maxScore = max(cnt, maxScore) return maxScore 단순하게 index를 기준으로 왼쪽은 0의 갯수를, 오른쪽은 1의 갯수를 세서 최댓값을 구하는 풀이이다. 풀이 2 class Solution: def maxScore(self, s: str) -> int: # 왼쪽 0의 갯수 + ..
문제 : https://leetcode.com/problems/search-a-2d-matrix/ 난이도 : Medium 풀이1 --- Brute Force class Solution: def searchMatrix(self, matrix: List[List[int]], target: int) -> bool: for arr in matrix: if target bool: lo, hi = 0, len(matrix) - 1 while lo row[-1]: lo = midRow + 1 else: l, h = 0, len(row) - 1 while l row[mid]: l = mid + 1 else: h = mid - 1 return False '이미 정렬이 되어있는 배열에서 원소를 찾는다!' -> 이진트리를 ..
문제: https://leetcode.com/problems/can-place-flowers/ 난이도: Easy 풀이 class Solution: def canPlaceFlowers(self, flowerbed: List[int], n: int) -> bool: flowerbed.insert(0, 0) flowerbed.append(0) emptyCnt = 0 # 0이 연달아 3개면 심기 가능 flower = 0 # 심은 꽃 갯수 for fb in flowerbed: if fb == 0: emptyCnt += 1 else: emptyCnt = 0 # 리셋 if emptyCnt == 3: flower += 1 emptyCnt = 1 if flower == n: return True return False
문제: https://leetcode.com/problems/best-time-to-buy-and-sell-stock-with-transaction-fee/ 난이도: Medium You are given an array prices where prices[i] is the price of a given stock on the ith day, and an integer fee representing a transaction fee. Find the maximum profit you can achieve. You may complete as many transactions as you like, but you need to pay the transaction fee for each transaction. N..
