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