### 062 Unique Paths

```/**
*
* Ashish Patel
* e: ashishsushilPatel@gmail.com
* w: https://ashish.me
*
*/

/*
* 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).
*
* Example 1:
*
* 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 -> Right -> Down
* 2. Right -> Down -> Right
* 3. Down -> Right -> Right
* Example 2:
*
* Input: m = 7, n = 3
* Output: 28
*
*
* Constraints:
*
* 1 <= m, n <= 100
* It's guarantee
*/

function uniquePaths(m, n) {
let rows = new Array(m).fill(0);
let matrix = rows.map(v => new Array(n).fill(1))
for (let i = 1; i < m; i++) {
for (let j = 1; j < n; j++) {
matrix[i][j] = matrix[i][j-1] + matrix[i-1][j]
}
}
return matrix[m-1][n-1]
}

test('unique Paths', () => {
expect(uniquePaths(3, 2)).toEqual(3)
expect(uniquePaths(7, 3)).toEqual(28)
});```

Created 2020-03-20T20:39:49+00:00, updated 2020-03-25T13:38:42+00:00 · History · Edit