Leetcode: Unique paths

A robot is located at the top-left corner of a m x n grid (marked 'Start' in the diagram below).

The robot can only move either down or right at any point in time. The robot is trying to reach the bottom-right corner of the grid (marked 'Finish' in the diagram below).

How many possible unique paths are there?

Above is a 3 x 7 grid. How many possible unique paths are there?

Note: m and n will be at most 100.

Solution:

public class Solution {
    public int uniquePaths(int m, int n) {
        int[][] paths = new int[m][n];
        paths[0][0] = 1;
        for(int row=0; row < m; row++)
        {
            for(int col = 0; col < n; col++)
            {
                paths[row][col] += row>0 ? paths[row-1][col] : 0;
                paths[row][col] += col>0 ? paths[row][col-1] : 0;
            }
        }
        return paths[m-1][n-1];
    }
}