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.
Code: (Dynamic Programming)
class Solution {
public:
int uniquePaths(int m, int n) {
int mat[101][101] = {0};
mat[0][1] = 1;
for (int i = 1; i <= m; i++)
for (int j = 1; j <= n; j++)
mat[i][j] = mat[i-1][j] + mat[i][j-1];
return mat[m][n];
}
};