# 3.09.2023 [62. Unique Paths]
Unique paths count, moving `right-down` from `top-left` to `bottom-right`
3.09.2023
62. Unique Paths medium
blog post
Join me on Telegram
https://t.me/leetcode_daily_unstoppable/328
Problem TLDR
Unique paths count, moving right-down
from top-left
to bottom-right
Intuition
On each cell, the number of paths is a sum of direct up
number and direct left
number.
Approach
Use single row array, as only previous up row is relevant
Complexity
Time complexity:
O(nm)Space complexity:
O(m)
Code
fun uniquePaths(m: Int, n: Int): Int {
val row = IntArray(n) { 1 }
for (y in 1..<m)
for (x in 1..<n)
row[x] += row[x - 1]
return row.last()
}