### LeetCode Challenge #62. Unique Paths

There is a robot on an `m x n` grid. The robot is initially located at the top-left corner (i.e., `grid[0][0]`). The robot tries to move to the bottom-right corner (i.e., `grid[m - 1][n - 1]`). The robot can only move either down or right at any point in time.

Given the two integers `m` and `n`, return the number of possible unique paths that the robot can take to reach the bottom-right corner.

The test cases are generated so that the answer will be less than or equal to `2 * 109`.

Example 1:

```Input: m = 3, n = 7
Output: 28
```

Example 2:

```Input: m = 3, n = 2
Output: 3
Explanation: From the top-left corner, there are a total of 3 ways to reach the bottom-right corner:
1. Right -> Down -> Down
2. Down -> Down -> Right
3. Down -> Right -> Down
```

Constraints:

• `1 <= m, n <= 100`
##### Video Solution
###### C++ Solution
```				```
class Solution {
public:
int mazepath(int i, int j, int n, int m,vector<vector<int>> &dp)
{
if(i==n-1 and j==m-1)return 1;
if(i>=n || j>=m)return 0;
if(dp[i][j]!=-1)return dp[i][j];
return dp[i][j]=mazepath(i,j+1,n,m,dp)+mazepath(i+1,j,n,m,dp);
}
int uniquePaths(int m, int n) {
vector<vector<int>> dp(m,vector<int>(n,-1));
return mazepath(0,0,m,n,dp);
}
};
```
```