Leetcode 67: Add Binary

Sun, 15 Feb 2026 16:40:02 +0700

Approach:

Intuition

The goal is to add two given string a and b, which represent the numbers in binary. We can think of it as two row of digits, add each column from the right to left, keep track the carry bit (like 1 + 1 results in 0 and carry 1 to the next row) and build the result string step by step.

Leetcode 110: Balanced Binary Tree

Sun, 08 Feb 2026 15:48:58 +0700

#110Balanced Binary Tree Easy →

Approach: DFS

Intuition

The problem asks us to determine whether a binary tree is balanced. A binary tree is balanced if the height difference between the left and right subtrees of any node is at most 1.

Easy on hungln

Leetcode 67: Add Binary

Approach:

Intuition

Leetcode 110: Balanced Binary Tree

Approach: DFS

Intuition