Leetcode 97. Interleaving String

https://leetcode.com/problems/interleaving-string/

DP.
Solution:

# T:O(m*n) S:O(m+n)
class Solution:
    # @return a boolean
    def isInterleave(self, s1, s2, s3):
        if len(s1)+len(s2)!=len(s3): return False
        dp=[[False for i in range(len(s2)+1)] for j in range(len(s1)+1)]
        dp[0][0]=True
        for i in range(1,len(s1)+1):
            dp[i][0] = dp[i-1][0] and s3[i-1]==s1[i-1]
        for i in range(1,len(s2)+1):
            dp[0][i] = dp[0][i-1] and s3[i-1]==s2[i-1]
        for i in range(1,len(s1)+1):
            for j in range(1,len(s2)+1):
                dp[i][j] = (dp[i-1][j] and\
          s1[i-1]==s3[i+j-1]) or (dp[i][j-1] and s2[j-1]==s3[i+j-1])
        return dp[len(s1)][len(s2)]

Run Time: 64 ms