trapping-rain-water py3

0042_trapping-rain-water/python3/imaginary_grid.py

@@ -0,0 +1,33 @@
+# Time: O(N · H) where H is the maximum height
+# Space: O(1)
+
+class Solution:
+    def trap(self, height: List[int]) -> int:
+        maxh = 0
+        
+        for h in height:
+            maxh = max(h, maxh)
+        
+        land_width = len(height)
+        output = 0
+        
+        for i in range(maxh):
+            row_output = 0
+            trough_output = 0
+            trough_start = -1
+            
+            for j in range(land_width):
+                # A block is present
+                if height[j] >= i + 1:
+                    row_output += trough_output
+                    trough_start = j
+                    trough_output = 0
+                elif trough_start >= 0:
+                    trough_output += 1
+        
+            output += row_output
+        
+        return output
+            
+                
+