[LeetCode] 404. Sum of Left Leaves

轉自LeetCode

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>

通常 tree 的問題，不是 DFS 就是 BFS

那實作的方式，就有 iterative 和 recursive 兩種

這邊就按照提意來寫就可以

code 如下

C++，Iterative

C++，Recursive