Question:
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
.
Anwser 1:
/**
* Definition for binary tree
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode(int x) : val(x), left(NULL), right(NULL) {}
* };
*/
class Solution {
public:
void calSum(TreeNode *root, int val, int &sum){
if(root == NULL){
return;
}
if(root->left == NULL && root->right == NULL){
sum += root->val + val * 10;
return;
}
calSum(root->left, val * 10 + root->val, sum);
calSum(root->right, val * 10 + root->val, sum);
}
int sumNumbers(TreeNode *root) {
// Start typing your C/C++ solution below
// DO NOT write int main() function
int sum = 0;
calSum(root, 0, sum);
return sum;
}
};