added solution 2 for sum of left leaves

david-legend · david-legend · commit c0883b97437b · 2022-11-21T05:24:04.000Z
diff --git a/leetcode/src/binary_trees/lc_404_sum_of_left_leaves/sum_of_left_leaves.py b/leetcode/src/binary_trees/lc_404_sum_of_left_leaves/sum_of_left_leaves.py
@@ -21,4 +21,27 @@ def sum_left_leaves_helper(node):
     result = [0]
     sum_left_leaves_helper(root)
 
-    return result[0]
+    return result[0]
+
+
+
+# Solution 2
+def sumOfLeftLeaves(root):
+    def sumOfLeftLeavesHelper(node):
+        nonlocal left_sum
+        if node is None:
+            return False
+        
+        if node.left:
+            if node.left.left is None and node.left.right is None:
+                left_sum += node.left.val
+            else:
+                sumOfLeftLeavesHelper(node.left)
+        
+            
+        sumOfLeftLeavesHelper(node.right)
+        
+    left_sum = 0
+    sumOfLeftLeavesHelper(root)
+        
+    return left_sum
