题目：

Balanced strings are those that have an 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 split 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] is either 'L' or 'R'.
• s is a balanced string.

思路：

easy题，当一个字符串内L和R的数量一样多时即为平衡字符串。基础思路是遍历字符串，用三个计数器，如果遇到L则 l加一；如果遇到R则 r加一；当l和r相等时，说明前面出现了一个平衡字符串，则count加一，然后把l和r清空，直到遍历完字符串，返回count即可。

代码：

class Solution {
public:
    int balancedStringSplit(string s) {
        int r = 0, l = 0, count = 0;
        for (auto a : s) {
            if (a == 'R')
                r++;
            else if (a == 'L')
                l++;
            if (l != 0 && l == r) {
                count++;
                l = r = 0;
            }
        }
        return count;
    }
};