add: 二叉树的最近公共祖先

src/tree/subtree-of-another-tree.js

@@ -0,0 +1,27 @@
+/**
+ * Definition for a binary tree node.
+ * function TreeNode(val, left, right) {
+ *     this.val = (val===undefined ? 0 : val)
+ *     this.left = (left===undefined ? null : left)
+ *     this.right = (right===undefined ? null : right)
+ * }
+ */
+/**
+ * @param {TreeNode} s
+ * @param {TreeNode} t
+ * @return {boolean}
+ */
+export const isSubtree = function (s, t) {
+  if (!s && t) {
+    return false
+  }
+
+  const linkNode = function (node, target) {
+    if ((!node && target) || (node && !target)) return false
+    if (!node && !target) return true
+
+    return node.val === target.val ? linkNode(node.left, target.left) && linkNode(node.right, target.right) : false
+  }
+
+  return linkNode(s, t) || isSubtree(s.left, t) || isSubtree(s.right, t)
+}