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.
Note: A leaf is a node with no children.
Example:
Input: [1,2,3]
1
/
2 3
Output: 25
Explanation:
The root-to-leaf path 1->2 represents the number 12.
The root-to-leaf path 1->3 represents the number 13.
Therefore, sum = 12 + 13 = 25.
Example 2:
Input: [4,9,0,5,1]
4
/
9 0
/
5 1
Output: 1026
Explanation:
The root-to-leaf path 4->9->5 represents the number 495.
The root-to-leaf path 4->9->1 represents the number 491.
The root-to-leaf path 4->0 represents the number 40.
Therefore, sum = 495 + 491 + 40 = 1026.
func sumNumbers(root *TreeNode) int {
if root == nil {
return 0
}
res := 0
dfs(root, 0, &res)
return res
}
func dfs(curr *TreeNode, path int, paths *int) {
if curr.Left == nil && curr.Right == nil {
fmt.Println()
*paths += path*10+curr.Val
}
if curr.Left != nil {
dfs(curr.Left, path*10+curr.Val, paths)
}
if curr.Right != nil {
dfs(curr.Right, path*10+curr.Val, paths)
}
}
