Unique Paths
Updated Jan 31, 2026
Problem
There is a robot on an m x n grid. The robot is initially located at the top-left corner (i.e., grid[0][0]). The robot tries to move to the bottom-right corner (i.e., grid[m - 1][n - 1]). 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.
Constraints
1 <= m, n <= 100
Examples
Example 1
Input:
m = 3, n = 7
Output:
28
Example 2
Input:
m = 3, n = 2
Output:
3
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
Function Signature
def uniquePaths(self, m: int, n: int) -> int
How to Submit
Implement a Solution class with a uniquePaths method.
Your method will be called with the input parameters and should return the answer.