bugfix

Author: Partho Biswas

algoexpert.io/python/Youngest_Common_Ancestor.py

@@ -6,9 +6,9 @@ def get_youngest_common_ancestor(top_ancestor, descendant_one, descendant_two):
     depth_one = get_descendant_depth(descendant_one, top_ancestor)
     depth_two = get_descendant_depth(descendant_two, top_ancestor)
     if depth_one > depth_two:
-        return backtrack_ancestral_tree()
+        return backtrack_ancestral_tree(descendant_one, descendant_two, depth_one - depth_two)
     else:
-        return backtrack_ancestral_tree()
+        return backtrack_ancestral_tree(descendant_two, descendant_one, depth_two - depth_one)
 
 
 def get_descendant_depth(descendant, top_ancestor):

leetcode.com/python/#286 - Walls and Gates.py

@@ -0,0 +1,66 @@
+class Solution(object):
+    def wallsAndGates(self, rooms):
+        """
+        :type rooms: List[List[int]]
+        :rtype: None Do not return anything, modify rooms in-place instead.
+        """
+        gateDistanceGrid = [['-inf' for value in row] for row in rooms]
+        for i in rooms:
+            for j in rooms[j]:
+                if gateDistanceGrid[i][j] is not '-inf':
+                    continue
+                else:
+                    gateDistanceGrid[i][j] = 'INF'
+                    gateDistance = self.traverseNode(i, j, rooms, gateDistanceGrid)
+                    if gateDistance > 0:
+                        gateDistanceGrid[i][j] = gateDistance
+        return gateDistanceGrid
+
+
+
+    def traverseNode(self, i, j, rooms, gateDistanceGrid):
+        gateDistance = 0
+        nodesToExplore = [[i, j]] # This is a queue, because we are performing BFS
+        while nodesToExplore:
+            currentNode = nodesToExplore.pop(0)
+            i = currentNode[0]
+            j = currentNode[1]
+            if rooms[i][j] == -1:
+                continue
+            if rooms[i][j] == 0:
+                gateDistance += 1
+                gateDistanceGrid[i][j] = gateDistance
+                break
+            unvisitedNeighbour = self.getUnvisitedNeighbour(i, j, rooms, gateDistanceGrid)
+            for neighbour in unvisitedNeighbour:
+                nodesToExplore.append(neighbour)
+        return gateDistance
+
+
+
+    def getUnvisitedNeighbour(self, i, j, rooms, gateDistanceGrid):
+        unvisitedNeighbours = []
+        if i > 0:
+            unvisitedNeighbours.append([i - 1, j])
+        if i < len(rooms) - 1:
+            unvisitedNeighbours.append([i + 1, j])
+        if j > 0:
+            unvisitedNeighbours.append([i, j - 1])
+        if j < len(rooms[0]) - 1:
+            unvisitedNeighbours.append([i, j + 1])
+        return unvisitedNeighbours
+
+
+
+
+# Driver Code
+sol = Solution()
+gateDistanceGrid = sol.wallsAndGates()
+
+
+
+
+
+
+
+