Sync LeetCode submission Runtime - 3 ms (29.32%), Memory - 19 MB (13.20%)

Author: jimit105

0112-path-sum/README.md

@@ -16,7 +16,7 @@
 <pre>
 <strong>Input:</strong> root = [1,2,3], targetSum = 5
 <strong>Output:</strong> false
-<strong>Explanation:</strong> There two root-to-leaf paths in the tree:
+<strong>Explanation:</strong> There are two root-to-leaf paths in the tree:
 (1 --&gt; 2): The sum is 3.
 (1 --&gt; 3): The sum is 4.
 There is no root-to-leaf path with sum = 5.

0112-path-sum/solution.py

@@ -1,23 +1,23 @@
-# Approach 1 - Recursion
+# Approach 1: Recursion
 
-# Time: O(N)
-# Space: O(N) in worst case, O(log N) in best case
+# Time: O(n)
+# Space: O(n) in worst base, O(log n) in best case
 
 # Definition for a binary tree node.
 # class TreeNode:
 #     def __init__(self, val=0, left=None, right=None):
 #         self.val = val
 #         self.left = left
 #         self.right = right
-
 class Solution:
     def hasPathSum(self, root: Optional[TreeNode], targetSum: int) -> bool:
         if not root:
             return False
-        
+
         targetSum -= root.val
-        if not root.left and not root.right:
+
+        if not root.left and not root.right: # reached leaf
             return targetSum == 0
-        
+
         return self.hasPathSum(root.left, targetSum) or self.hasPathSum(root.right, targetSum)