Código:
#include <windows.h>
#include <math.h>
#include <iostream>
using namespace std;
int main()
{
char a;
char b;
char c;
char d;
char e;
char f;
char g;
char h;
char i;
cout << "Introduce 9 caracteres para el tablero de 3 en raya:";
cin >> a;
cin >> b;
cin >> c;
cin >> d;
cin >> e;
cin >> f;
cin >> g;
cin >> h;
cin >> i;
cout << endl << endl;
cout << "|----------|";
cout << "| " << a << "|" << b << " | " << c < " |";
cout << "|----------|";
cout << "| " << d << "|" << e << " | " << f < " |";
cout << "|----------|";
cout << "| " << g << "|" << h << " | " << i < " |";
cout << "|----------|";
return 0;
}