Given two binary trees, write a function to check if they are the same or not.
[Read More]

## 787. Cheapest Flights Within K Stops

### Medium

There are n cities connected by m flights. Each fight starts from city u and arrives at v with a price w.
[Read More]

## 73. Set Matrix Zeroes

### 矩阵赋零（Medium）

Given a m x n matrix, if an element is 0, set its entire row and column to 0. Do it in-place.
[Read More]

## 72. Edit Distance

### 编辑距离 (Hard)

Description
Given two words word1 and word2, find the minimum number of operations required to convert word1 to word2.
[Read More]

## 70. Climbing Stairs

### Easy

You are climbing a stair case. It takes n steps to reach to the top.
[Read More]

## 704. Binary Search

Given a sorted (in ascending order) integer array nums of n elements and a target value, write a function to search target in nums. If target exists, then return its index, otherwise return -1.
[Read More]