c – How to check if the seat is free and if you are not asking the user to write again by inserting an & # 39; X & # 39; in the occupied space?

I need the user to insert where he wants to sit by reporting the row and column he wants, if the user chooses the position 0-1 the program will record and save to a file txt later that information, and will enter a file looping to register a new user, where he will type in the position he wants and if a position is written where the program is already occupied by another user will not accept placing a X instead to show that it is busy.

Follow the code …

# include
# include 
void main () {noun

printf (" n  nSchool your seat:  n  n");
int m, n, row, seat;
int places[10][16];

for (m = 1, m <10; m ++) {
for (n = 1; n <16; n ++) {
printf ("[%d- %d]"M, n);
printf (" n");

printf (" nFileira desired:");
scanf ("% d", & Row);
printf ("Desired seat:");
scanf ("% d", and seat);

system ("pause");