Code

 Header...
//
// Demonstrate the break statement as part of a noughts and crosses program
//

int squareisplayed (int x,int y);// Written elsewhere

 int main(){
   ... 

»  int x, y;

»  printf("Welcome to the noughts and crosses program\n");

»  while (1==1) {
»    printf("Please enter the x and y coordinates in the range 1-3 ");

»    if (scanf("%d %d", &x, &y)!=2) {
»      fprintf(stderr, "Could not read x and y coordinates\n");
»      exit(99);
}
    else if (x<1||x>3||y<1||y>3) 
      printf("\nThe inputs are in the wrong range, please try again.\n\n");
    else if (squareisplayed(x, y)) 
      printf("\nSorry, the square (%i, %i) has already been played\n", x, y);
    else 
      break;
  }

»  printf("Your move is: (%d, %d)\n", x, y);
»  return 0;
}

Data