# Leetcode 62 - Unique paths

Note:

• The DP formula is DP[i][j] = DP[i-1][j] + DP[i][j-1];
• Every element in this 2D array means how many paths there are from [0][0] to [i][j].
• To initialize our array, we just need to fill the first row and col with 1 because there is only 1 way from (0,0) to those places.

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?

Example 1: