剑指Offer 26. 树的子结构

 1 /**
 2  * Definition for a binary tree node.
 3  * function TreeNode(val) {
 4  *     this.val = val;
 5  *     this.left = this.right = null;
 6  * }
 7  */
 8 /**
 9  * @param {TreeNode} A
10  * @param {TreeNode} B
11  * @return {boolean}
12  */
13 var isSubStructure = function(A, B) {
14     if(A == null || B == null) return false;
15     return (recur(A, B) || isSubStructure(A.left, B) || isSubStructure(A.right, B));
16     //return (A != null && B != null) && (recur(A, B) || isSubStructure(A.left, B) || isSubStructure(A.right, b));
17 };
18 
19 const recur = (A, B) => {
20     if(B == null) { //B为空说明当前节点前面的节点已经匹配完毕
21         return true;
22     }
23     if(A == null || A.val != B.val) {//A为空说明B不为空
24         return false;
25     }
26     return recur(A.left, B.left) && recur(A.right, B.right);
27 }