Given a binary tree containing digits from 0-9
only, each root-to-leaf path could represent a number.
An example is the root-to-leaf path 1->2->3
which represents the number 123
.
Find the total sum of all root-to-leaf numbers.
For example,
1 / 2 3
The root-to-leaf path 1->2
represents the number 12
.
The root-to-leaf path 1->3
represents the number 13
.
Return the sum = 12 + 13 = 25
.
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/** * 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: string _covert_to_string(int i) { char c[8]; snprintf(c,7, "%d", i); return static_cast<string>(c); } void get_sum_of_tree(TreeNode* root, string branch_value, int &sum) { if (NULL == root) { return; } else if (root->left == NULL && root->right == NULL) { branch_value = branch_value + _covert_to_string(root->val); sum += atoi(branch_value.c_str()); return; } branch_value = branch_value + _covert_to_string(root->val); get_sum_of_tree(root->left, branch_value, sum); get_sum_of_tree(root->right, branch_value, sum); } int sumNumbers(TreeNode* root) { string b = ""; int sum = 0; get_sum_of_tree(root, b, sum); return sum; } };