Main.cpp:12:5: error: use of undeclared identifier 'gets'
    gets(n);
    ^
Main.cpp:16:13: error: use of undeclared identifier 's'
        t = s[j];
            ^
Main.cpp:17:9: error: use of undeclared identifier 's'
        s[j] = s[i];
        ^
Main.cpp:17:16: error: use of undeclared identifier 's'
        s[j] = s[i];
               ^
Main.cpp:18:9: error: use of undeclared identifier 's'
        s[i] = t;
        ^
Main.cpp:20:38: error: use of undeclared identifier 's'
    cout << "\nReverse string : " << s;
                                     ^
6 errors generated.