LeetCode 62. Unique Paths

2. Unique Paths

My Submissions QuestionEditorial Solution

Total Accepted: 84185 Total Submissions: 233521 Difficulty: Medium

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) {
int a[100][100];
for(int i = 0; i < m; i++) {
for(int j = 0; j < n; j++) {
if(i == 0 || j == 0)
a[i][j] = 1;
else
a[i][j] = a[i - 1][j] + a[i][j - 1];
}
}
return a[m - 1][n - 1];
}
};