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.

题意：一个机器人位于矩阵的左上角，它只能向右或向下走，问走到右下角的路径数。

思路：简单的dp

class Solution {public:    int uniquePaths(int m, int n) {        vector<vector<int> > f(m, vector<int>(n));               for (int i = 0; i < n; i++)            f[0][i] = 1;        for (int i = 0; i < m; i++)             f[i][0] = 1;        for (int i = 1; i < m; i++)             for (int j = 1; j < n; j++)                f[i][j] = f[i-1][j] + f[i][j-1];        return f[m-1][n-1];    }};