Update 112_path_sum.md

Author: Joseph Luce

leetcode/easy/112_path_sum.md

@@ -27,7 +27,7 @@ class Solution:
         return has_path_sum_helper(root, 0, sum)
 ```
 
-## Iterative Solution (Lazy Approach)
+## Lazy Iterative Solution
 - Runtime: O(N)
 - Space: O(N)
 - N = Number of nodes in tree
@@ -58,6 +58,9 @@ class Solution:
 
 
 ## Inorder Iterative Solution (Preferred Approach)
+- Runtime: O(N)
+- Space: O(N)
+- N = Number of nodes in tree
 
 This implementation is similar to the above approach, however, it falls in line with how you would do an inorder traversal iteratively due to backtracking. It is important to fully understand this implementation. Try drawing it out if it confuses you, it will click better. Then try it doing pre-order and post-order traversals.