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".

Example 4:
Input: s = "RLRRRLLRLL"
Output: 2
Explanation: s can be split into "RL", "RRRLLRLL", since each substring contains an equal number of 'L' and 'R'
Constraints:
1 <= s.length <= 1000
s[i] = 'L' or 'R'

最开始看到这个题目想用stack，后面发现，完全没有这个必要呀，直接简单统计遇到L就加1 R减1，当计数为0时则认为这是一个分隔。

class Solution {
public:
    int balancedStringSplit(string s) {
        int cnt = 0,res = 0;
        for(auto c:s)
        {
            cnt +=  (c=='R')? 1:-1;
            if(cnt == 0)
                ++res;
        }
        return res;
    }
};

运行结果：

Runtime: 0 ms, faster than 100.00% of C++ online submissions for Split a String in Balanced Strings.
Memory Usage: 6.5 MB, less than 5.67% of C++ online submissions for Split a String in Balanced Strings.