Created 572-Subtree-of-Another-Tree

Author: loczek

typescript/572-Subtree-of-Another-Tree.ts

@@ -0,0 +1,42 @@
+/**
+ * Definition for a binary tree node.
+ * 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 isSubtree(root: TreeNode | null, subRoot: TreeNode | null): boolean {
+  if (subRoot === null) return true;
+  if (root === null) return false;
+
+  if (isSameTree(root, subRoot)) {
+    return true;
+  }
+
+  let left = isSubtree(root.left, subRoot);
+  let right = isSubtree(root.right, subRoot);
+
+  return left || right;
+}
+
+function isSameTree(p: TreeNode | null, q: TreeNode | null): boolean {
+  if (p === null && q === null) return true;
+
+  if ((p === null && q !== null) || (p !== null && q === null)) return false;
+
+  let leftSame = isSameTree(p.left, q.left);
+  let rightSame = isSameTree(p.right, q.right);
+
+  if (p.val === q.val && leftSame && rightSame) {
+    return true;
+  }
+
+  return false;
+}