【LeetCode 19】541.反转字符串II

class Solution {
public:
    string reverseStr(string s, int k) {
        int now=0;
        while(now<s.size()){//now一直遍历字符串，判断能反转够
            if(now+k<s.size()){//前k个反转
                //正常反转，revers反转库函数
                reverse(s.begin()+now,s.begin()+now+k);
            }else{//后k个反转
                reverse(s.begin()+now,s.end());
            }
            now+=2*k;//now指针移动
        }
        return s;
    }
};