roodz

#if defined(_WIN32) || defined (_WIN64)
    #include <windows.h>
    #define OS_WIN 1
#endif

int main()
{
    #ifdef OS_WIN
        SetConsoleOutputCP(1251);
        SetConsoleCP(1251);
    #else
        setlocale(LC_CTYPE, "Russian");
    #endif

    // ...

    return 0;
}