Medium

Quiz

#62 Unique Paths

APPROACH

A robot starts at the top-left cell of an m x n grid and can only move right or down toward the bottom-right cell. Given m and n, return the number of distinct paths. The answer will not exceed 2 * 10⁹.

Example 1:

Input: m = 3, n = 7

Output: 28

Example 2:

Input: m = 3, n = 2

Output: 3

Explanation: From the top-left corner, there are a total of 3 ways to reach the bottom-right corner:

1. Right -> Down -> Down

2. Down -> Down -> Right

3. Down -> Right -> Down

1 of 4

1:00

What is the optimal approach for this problem?