Leetcode 1221. Split a String in Balanced Strings

Problem statement

https://leetcode.com/problems/split-a-string-in-balanced-strings/

Solution

Replace all R with 1 and all L with -1, then use accumulate and calculate number of zeroes.

Complexity

It is O(n) for time and space.

Code

class Solution:
    def balancedStringSplit(self, s):
        s = [1 if x == "R" else -1 for x in s]
        acc = list(accumulate(s))
        return acc.count(0)