LeetCode-62-Unique Paths DP水题

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