Update BSTMinDepth comments

Author: kumailn

Python/BST_Min_Depth.py

@@ -1,17 +1,22 @@
-def minDepth(self, root):
-        """
-        :type root: TreeNode
-        :rtype: int
-        """
-        queue = [root]
-        current = []
-        mindepth = 0
+#Question: Given the root of a tree, find the minimum dept the tree goes
+#Solution: Use a BFS traversal to find the first leaf node of the tree
+#Difficulty: Easy
+
+def minDepth(root):
+        #Define queue, current queue and a mindepth variable
+        queue = [root]; current = []; mindepth = 0
+        #If our current node is null, the depth is 0, so return 0
         if not root: return mindepth
+        #As long as our queue exists
         while queue:
+            #For every element in our queue
             for i in queue:
+                #If we have reached a leaf node, we can return 1+mindepth
                 if not i.left and not i.right: return mindepth + 1
+                #Else we append the left and right children to our queue (See BFS traversal)
                 if i.left: current.append(i.left)
                 if i.right: current.append(i.right)
+            #Set queue to current queue, current to empty list and add one to our mindepth because we're now on a new level
             queue = current
             current = []
             mindepth += 1