I need some help creating a rand number that will not come up with a number that has already been called. For example, a tic-tac-toe game which allows a player to play against a computer. This code will limit the numbers from 1-9, but they still repeat.

Code:
#include <iostream>
#include <cstdlib>
#include <time.h>
const int LOW = 1;
const int HIGH = 9;

using namespace std;

int main()
{
int comp_choice;
time_t seconds;
time(&seconds);
srand((unsigned int) seconds);
comp_choice = rand() % (HIGH - LOW + 1) + LOW;
cout<<"the computer picked: "<<comp_choice;
return 0;
}