62. Unique Paths - LeetCode

import math


class Solution1:
    def uniquePaths(self, m: int, n: int) -> int:
        return math.comb((m - 1) + (n - 1), (n - 1))


class Solution:
    def uniquePaths(self, m: int, n: int) -> int:
        dp = [1] + [0 for _ in range(n - 1)]
        for _ in range(m):
            for i in range(n - 1):
                dp[i + 1] += dp[i]
        return dp[n - 1]