344 反转字符串 541反转字符串II

344没啥好说的

class Solution {
public:
    void reverseString(vector<char>& s) {
        int len = s.size();
        int left =  0;
        int right =  len-1;
        
        while (left < len / 2 )
        {
            char temp = s[left];
            s[left] = s[right];
            s[right] = temp;
            --right;
            ++left;
        }
    }
};

541

class Solution {
public:
    string reverseStr(string s, int k) {

        int len = s.size();
       
       for(int i = 0; i < len ; i = i + 2*k)
       {
        if( i+k > len )    
            reverse( s.begin() + i, s.end() );
        else
            reverse( s.begin() + i, s.begin() + i + k);
        }

       return s;
    }
};