[LeetCode]1221. Split a String in Balanced Strings

Balanced strings are those who have equal quantity of 'L' and 'R' characters.

Given a balanced string s split it in the maximum amount of balanced strings.

Return the maximum amount of splitted balanced strings.

 

Example 1:

Input: s = "RLRRLLRLRL"
Output: 4
Explanation: s can be split into "RL", "RRLL", "RL", "RL", each substring contains same number of 'L' and 'R'.
Example 2:

Input: s = "RLLLLRRRLR"
Output: 3
Explanation: s can be split into "RL", "LLLRRR", "LR", each substring contains same number of 'L' and 'R'.
Example 3:

Input: s = "LLLLRRRR"
Output: 1
Explanation: s can be split into "LLLLRRRR".
 

Constraints:

1 <= s.length <= 1000
s[i] = 'L' or 'R'

 

python3:

class Solution:
    def balancedStringSplit(self, s: str) -> int:
        l = 0
        r = 0
        rst = 0
        for s_str in s:
            if s_str == 'L':
                l += 1
            elif s_str == 'R':
                r += 1
            if l == r:
                rst += 1
                l = 0
                r = 0
        return rst