Day: November 16, 2016
Sum of Left Leaves
Problem:
Find the sum of all left leaves in a given binary tree.
Example:
3
/ \
9 20
/ \
15 7
There are two left leaves in the binary tree, with values 9 and 15 respectively. Return 24.
Solution:
For tree traversal, think in recursion way first. The point is to catch the left leaves. So the base case includes catching a left leaf. Then just recursively call itself on both left subtree and right subtree to find all the left leaves.