Formatted question description: https://leetcode.ca/all/62.html
62 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. @tag-array
Using Dynamic Programming to solve, you can maintain a two-dimensional array dp, where
dp[i][j] represents the number of different moves to the current position, and then the state transition equation can be obtained as:
dp[i][j ] = dp[i-1][j] + dp[i][j-1], here in order to save space, use a one-dimensional array dp, refresh line by line.