feat(soobing): week15 > subtree-of-another-tree

Author: soobing

subtree-of-another-tree/soobing.ts

@@ -0,0 +1,33 @@
+/**
+ * 문제 설명
+ * - 두 개의 이진트리 중, subTree가 존재하는지 확인하는 문제
+ *
+ * 아이디어
+ * 1) DFS + isSameTree 체크
+ */
+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 isSameTree(tree1: TreeNode | null, tree2: TreeNode | null) {
+  if ((tree1 && !tree2) || (!tree1 && tree2)) return false;
+  if (tree1 === null && tree2 === null) return true;
+  if (tree1?.val !== tree2?.val) return false;
+  return (
+    isSameTree(tree1?.left ?? null, tree2?.left ?? null) &&
+    isSameTree(tree1?.right ?? null, tree2?.right ?? null)
+  );
+}
+
+function isSubtree(root: TreeNode | null, subRoot: TreeNode | null): boolean {
+  if (!root) return false;
+  if (isSameTree(root, subRoot)) return true;
+  return isSubtree(root.left, subRoot) || isSubtree(root.right, subRoot);
+}