344. Reverse String

// 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;
    }
};