[devyejin] WEEK 06 solutions

container-with-most-water/devyejin.py

@@ -0,0 +1,17 @@
+from typing import List
+
+
+class Solution:
+    def maxArea(self, height: List[int]) -> int:
+        left, right = 0, len(height) - 1
+        answer = 0
+
+        while left < right:
+            answer = max(answer, (right - left) * min(height[left], height[right]))
+
+            if height[left] < height[right]:
+                left += 1
+            else:
+                right -= 1
+
+        return answer

design-add-and-search-words-data-structure/devyejin.py

@@ -0,0 +1,40 @@
+class WordDictionary:
+
+    def __init__(self):
+        self.root = {"$": False}
+
+    def addWord(self, word: str) -> None:
+        node = self.root
+        for ch in word:
+            if ch not in node:
+                node[ch] = {"$": False}
+            node = node[ch]
+        node["$"] = True
+
+    def search(self, word: str) -> bool:
+        def dfs(node, idx):
+            if idx == len(word):
+                return node.get("$", False)
+
+            ch = word[idx]
+
+            if ch == ".":
+                for key in node:
+                    if key == "$":
+                        continue
+                    if dfs(node[key], idx + 1):
+                        return True
+                return False
+            else:
+                if ch in node:
+                    return dfs(node[ch], idx + 1)
+                else:
+                    return False
+
+        return dfs(self.root, 0)
+
+# Your WordDictionary object will be instantiated and called as such:
+# obj = WordDictionary()
+# obj.addWord(word)
+# param_2 = obj.search(word)
+

longest-increasing-subsequence/devyejin.py

@@ -0,0 +1,27 @@
+from typing import List
+class Solution:
+    def lengthOfLIS(self, nums: List[int]) -> int:
+        def binary_search(target):
+            left, right = 0, len(result)
+
+            while left < right:
+                mid = (left + right) // 2
+                if result[mid] < target:
+                    left = mid + 1
+                else:
+                    right = mid
+            return left
+
+        result = []
+
+        for num in nums:
+            idx = binary_search(num)
+            if idx == len(result):
+                result.append(num)
+            else:
+                result[idx] = num
+
+        return len(result)
+
+
+

spiral-matrix/devyejin.py

@@ -0,0 +1,28 @@
+from typing import List
+
+
+class Solution:
+    def spiralOrder(self, matrix: List[List[int]]) -> List[int]:
+        dr = (0, 1, 0, -1)
+        dc = (1, 0, -1, 0)
+        r, c, d = 0, 0, 0
+
+        n, m = len(matrix), len(matrix[0])
+
+        result = []
+        VISITED = None
+        for _ in range(n * m):
+            result.append(matrix[r][c])
+            matrix[r][c] = VISITED
+
+            nr, nc = r + dr[d], c + dc[d]
+
+            if 0 <= nr < n and 0 <= nc < m and matrix[nr][nc] != VISITED:
+                r, c = nr, nc
+                continue
+
+            d = (d + 1) % 4
+            r += dr[d]
+            c += dc[d]
+
+        return result

valid-parentheses/devyejin.py

@@ -0,0 +1,15 @@
+class Solution:
+    def isValid(self, s: str) -> bool:
+        characters_dict = {')': '(', '}': '{', ']': '['}
+
+        stack = []
+        for ch in s:
+            if ch in characters_dict.values():
+                stack.append(ch)
+            elif ch in characters_dict:
+                if not stack or stack[-1] != characters_dict[ch]:
+                    return False
+                stack.pop()
+
+        return not stack
+