[jeldo3] Week6

container-with-most-water/jeldo.py

@@ -0,0 +1,13 @@
+class Solution:
+    # O(n), n = len(height)
+    def maxArea(self, height: list[int]) -> int:
+        max_amount = 0
+        l, r = 0, len(height) - 1
+        while l < r:
+            amount = min(height[l], height[r]) * (r - l)
+            max_amount = max(max_amount, amount)
+            if height[l] < height[r]:
+                l += 1
+            else:
+                r -= 1
+        return max_amount

spiral-matrix/jeldo.py

@@ -0,0 +1,18 @@
+class Solution:
+    # O(m*n), m = len(row), n = len(column)
+    def spiralOrder(self, m: list[list[int]]) -> list[int]:
+        dirs = [(0, 1), (1, 0), (0, -1), (-1, 0)]
+        result = []
+        visited = set()
+        heading, count = 0, 0
+        r, c = 0, 0
+        while count < len(m) * len(m[0]):
+            result.append(m[r][c])
+            visited.add((r, c))
+            count += 1
+            next_r, next_c = r + dirs[heading][0], c + dirs[heading][1]
+            if not (0 <= next_r < len(m) and 0 <= next_c < len(m[0])) or (next_r, next_c) in visited:
+                heading = (heading + 1) % 4
+                next_r, next_c = r + dirs[heading][0], c + dirs[heading][1]
+            r, c = next_r, next_c
+        return result

valid-parentheses/jeldo.py

@@ -0,0 +1,17 @@
+class Solution:
+    # O(n), n = len(s)
+    def isValid(self, s: str) -> bool:
+        parentheses = {
+            "(": ")",
+            "]": "]",
+            "{": "}",
+        }
+        stack = []
+        for ch in s:
+            if ch in parentheses.keys():
+                stack.append(ch)
+            elif stack and ch == parentheses[stack[-1]]:
+                stack.pop()
+            else:
+                return False
+        return len(stack) == 0