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.
/** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */class Solution {public: int sumOfLeftLeaves(TreeNode* root) { if(!root) return 0; else if(root->left){ TreeNode* lc = root->left; if(!lc->left && !lc->right){ return lc->val + sumOfLeftLeaves(root->right); }else{ return sumOfLeftLeaves(root->left) + sumOfLeftLeaves(root->right); } } else return sumOfLeftLeaves(root->left) + sumOfLeftLeaves(root->right); }};新闻热点
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