Math
Dynamic Programming
Combinatorics
There is a robot on an `m x n` grid. The robot is initially located at the **top-left corner**. The robot tries to move to the **bottom-right corner**. The robot can only move either down or right at any point in time.
Given the two integers `m` and `n`, return *the number of possible unique paths that the robot can take to reach the bottom-right corner*.
Example 1
Input: m = 3, n = 7
Output: 28
Example 2
Input: m = 3, n = 2
Output: 3
Constraints
- •
1 <= m, n <= 100 - •
The answer is guaranteed to be less than or equal to 2 * 10⁹.