upd

algorithms/labs/lab6/leetcode/3/solution.py

@@ -0,0 +1,20 @@
+from typing import List
+
+
+class Solution:
+    def trap(self, height: List[int]) -> int:
+        n = len(height)
+        if n == 0:
+            return 0
+        left = [0] * n
+        right = [0] * n
+        left[0] = height[0]
+        for i in range(1, n):
+            left[i] = max(left[i - 1], height[i])
+        right[-1] = height[-1]
+        for i in range(n - 2, -1, -1):
+            right[i] = max(right[i + 1], height[i])
+        ans = 0
+        for i in range(n):
+            ans += min(left[i], right[i]) - height[i]
+        return ans