Unique Paths (LC-0062)

class Solution:
    def uniquePaths(self, m, n):
        
        @lru_cache(maxsize=None)
        def rec(rx, cx):
            if rx == 0 or cx == 0:
                return 1
            p1 = rec(rx - 1, cx)
            p2 = rec(rx, cx - 1)
            return p1 + p2
        
        return rec(m - 1, n - 1)