class Solution(object):
    def minimumDeleteSum(self, s1, s2):
        """
        :type s1: str
        :type s2: str
        :rtype: int
        """
        prev = [0]
        for c in s2:
            prev.append(prev[-1] + ord(c))
        for i1, c1 in enumerate(s1, 1):
            nxtRow = [0] * (len(s2) + 1)
            o1 = ord(c1)
            nxtRow[0] = o1 + prev[0]
            for i2, c2 in enumerate(s2, 1):
                if c1 == c2:
                    nxtRow[i2] = prev[i2 - 1]
                else:
                    o2 = ord(c2)
                    nxtRow[i2] = min(prev[i2] + o1, nxtRow[i2 - 1] + o2)
            prev = nxtRow
        return nxtRow[len(s2)]

Add py solution for 712. Minimum ASCII Delete Sum for Two Strings
Add py solution for 712. Minimum ASCII Delete Sum for Two Strings

712. Minimum ASCII Delete Sum for Two Strings: https://leetcode.com/problems/minimum-ascii-delete-sum-for-two-strings/
