Leetcode-5222 Split a String in Balanced Strings(分割平衡字符串)

using namespace std;
typedef pair<int,int> P;
typedef long long ll;
#define _for(i,a,b) for(register int i = (a);i < b;i ++)
#define _rep(i,a,b) for(register int i = (a);i > b;i --)
#define INF 0x3f3f3f3f
#define MOD 100000000
#define maxn 1003
#define pb push_back
#define debug() printf("Miku Check OK!\n")


class Solution
{
    public:
        int balancedStringSplit(string s)
        {
            int rnt = 0;
            int k1 = 0,k2 = 0;
            _for(i,0,s.size())
            {
                if(s[i]=='L')
                    k1 ++;
                else
                    k2 ++;
                if(k1==k2)
                    rnt ++;
            }
            return rnt;
        }
};