LeetCoder -

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.

public class Solution {
    public int uniquePaths(int m, int n) {
        int way[][] = new int[m][n];
        for(int i=0;i<m;i++) {
            for(int j=0;j<n;j++) {
                if(i==0 || j==0) {
                    way[i][j] = 1;
                } else {
                    way[i][j] = way[i][j-1] + way[i-1][j];
                }
           }
        }
        return way[m-1][n-1];
    }
}

=======

public class Solution {
    public int uniquePaths(int m, int n) {
        if (m > n) {
            return uniquePaths(n, m);
        }
        int path[] = new int[m];
        path[0] = 1;
        for (int j = 0; j < n; j++) {
            for (int i = 0; i < m; i++) {
                if (i != 0) {
                    path[i] = path[i] + path[i - 1];
                }
            }
        }
        return path[m - 1];
    }
}