class Solution(object):
    def uniquePaths(self, m, n):
        """
        :type m: int
        :type n: int
        :rtype: int
        """
        dp = [ [0 for j in range(m)] for i in range(n)]
        dp[0][0] = 1
        for i in range(n):
            dp[i][0] = 1
        for j in range(m):
            dp[0][j] = 1
        for i in range(1,n):
            for j in range(1,m):
                dp[i][j] = dp[i-1][j] + dp[i][j-1]
        return dp[n-1][m-1]Copy