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.

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

Unique Paths

原文：http://www.cnblogs.com/li303491/p/4078870.html