-
Notifications
You must be signed in to change notification settings - Fork 41
/
solution.ts
25 lines (23 loc) · 731 Bytes
/
solution.ts
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
class TreeNode {
val: number
left: TreeNode | null
right: TreeNode | null
constructor (val?: number, left?: TreeNode | null, right?: TreeNode | null) {
this.val = (val === undefined ? 0 : val);
this.left = (left === undefined ? null : left);
this.right = (right === undefined ? null : right);
}
}
function preorderTraversal (root: TreeNode | null): number[] {
if (root === null) {
return [];
}
const result:number[] = [];
preorder(root, result);
return result;
}
function preorder (root:TreeNode, result:number[]) {
result.push(root.val);
root.left !== null && preorder(root.left, result);
root.right !== null && preorder(root.right, result);
}