C++ 7 ms
class Solution {\npublic:\n    string reverseStr(string s, int k) {\n        \n        \n        for( int i=0;i<s.length();i=i+(2*k))\n        {\n            \n
class Solution {\npublic:\n    string reverseStr(string s, int k) {\n        \n        \n        for( int i=0;i<s.length();i=i+(2*k))\n        {\n            \n            int l=i;\n            \n            int n= s.length()-1;\n            \n            int r = min(i+k-1,n);\n            \n           // int mid=(l+r)/2;\n            \n            while(l<r)\n            {\n                \n                swap(s[l],s[r]);\n                l++;r--;\n            }\n            \n            \n        }\n        \n        return s;\n        \n    }\n};
['C']