// My own solution class Solution {public:    string reverseString(string s) {        return string(s.crbegin(), s.crend());    }};

// My own solution class Solution {public:    string reverseString(string s) {        int n = s.size();        const char *p = s.c_str() + ((n - 1) * sizeof(char));        string str;        for(int i = 0; i < n; i++){            str += *p;            p = p - sizeof(char);        }        return str;    }};

// Learning from others' ideas class Solution {public:    string reverseString(string s) {        int n = s.size();        for(int i = 0; i < n / 2; i++){            char tmp = s[i];            s[i] = s[n - 1 - i];            s[n - 1 - i] = tmp;        }        return s;    }};