193rd Commit

README.md

@@ -172,13 +172,14 @@ Ace Coding Interview with 75 Qs
 | Binary Tree - DFS                            |                 |        |
 | -------------------------------------------- | --------------- | ------ |
 | 104. Maximum Depth of Binary Tree            | [Solution][104] | Easy   |
-| 872. Leaf-Similar Trees                      | Solution        | Easy   |
+| 872. Leaf-Similar Trees                      | [Solution][872] | Easy   |
 | 1448. Count Good Nodes in Binary Tree        | Solution        | Medium |
 | 437. Path Sum III                            | Solution        | Medium |
 | 1372. Longest ZigZag Path in a Binary Tree   | Solution        | Medium |
 | 236. Lowest Common Ancestor of a Binary Tree | Solution        | Medium |
 
 [104]: ./src/page-2/104.%20Maximum%20Depth%20of%20Binary%20Tree/maxDepth.ts
+[872]: ./src/page-9/872.%20Leaf-Similar%20Trees/leafSimilar.ts
 
 | Binary Tree - BFS                        |          |        |
 | ---------------------------------------- | -------- | ------ |

src/page-9/872. Leaf-Similar Trees/leafSimilar.test.ts

@@ -0,0 +1,20 @@
+import { generateBinaryTree } from '~/utils/binary-tree';
+
+import { leafSimilar } from './leafSimilar';
+
+describe('872. Leaf-Similar Trees', () => {
+  test('leafSimilar', () => {
+    {
+      const root1 = generateBinaryTree([3, 5, 1, 6, 2, 9, 8, null, null, 7, 4]);
+      // biome-ignore format: the array should not be formatted
+      const root2 = generateBinaryTree([3, 5, 1, 6, 7, 4, 2, null, null, null, null, null, null, 9, 8]);
+      expect(leafSimilar(root1, root2)).toBe(true);
+    }
+
+    {
+      const root1 = generateBinaryTree([1, 2, 3]);
+      const root2 = generateBinaryTree([1, 3, 2]);
+      expect(leafSimilar(root1, root2)).toBe(false);
+    }
+  });
+});

src/page-9/872. Leaf-Similar Trees/leafSimilar.ts

@@ -0,0 +1,42 @@
+import type { TreeNode } from '~/utils/binary-tree';
+
+type LeafSimilar = (root1: TreeNode | null, root2: TreeNode | null) => boolean;
+
+/**
+ * Accepted
+ */
+export const leafSimilar: LeafSimilar = (root1, root2) => {
+  // Helper function to collect all leaf values of a binary tree
+  const getLeaves = (root: TreeNode | null): number[] => {
+    const leaves: number[] = [];
+
+    // Depth-First Search (DFS) function to traverse the tree
+    const dfs = (node: TreeNode | null) => {
+      // If the node is null, return (do nothing)
+      if (node === null) return;
+
+      // If the node is a leaf (no left or right children), add its value to the leaves array
+      if (node.left === null && node.right === null) leaves.push(node.val);
+
+      // Recursively traverse the left subtree
+      dfs(node.left);
+
+      // Recursively traverse the right subtree
+      dfs(node.right);
+    };
+
+    // Start DFS traversal from the root to find all leaf nodes
+    dfs(root);
+
+    // Return the collected leaf values
+    return leaves;
+  };
+
+  // Get the leaf value sequences for both trees
+  const leaves1 = getLeaves(root1);
+  const leaves2 = getLeaves(root2);
+
+  // Compare the leaf value sequences for equality
+  // Convert both sequences to strings and check if they are identical
+  return JSON.stringify(leaves1) === JSON.stringify(leaves2);
+};