[LeetCode]#682. Baseball Game

Given two strings s and t, return true if they are equal when both are typed into empty text editors. '#' means a backspace character.

Note that after backspacing an empty text, the text will continue empty.

 

Example 1:

Input: s = "ab#c", t = "ad#c" Output: true Explanation: Both s and t become "ac".

Example 2:

Input: s = "ab##", t = "c#d#" Output: true Explanation: Both s and t become "".

Example 3:

Input: s = "a##c", t = "#a#c" Output: true Explanation: Both s and t become "c".

Example 4:

Input: s = "a#c", t = "b" Output: false Explanation: s becomes "c" while t becomes "b".

 

Constraints:

• 1 <= s.length, t.length <= 200
• s and t only contain lowercase letters and '#' characters.

 

class Solution:
    def calPoints(self, ops):
        ans=[]
        
        for i in ops:
            if i=="C":
                ans.pop()
            elif i=="D":
                ans.append(ans[-1]*2)
            elif i=="+":
                ans.append(ans[-1]+ans[-2])
            else:
                ans.append(int(i))
        return sum(ans)