Why does my code not compile on gradescope?

#include

#include

#define SIZE $3$

void printBoard$($char board$[$SIZE$][$SIZE$])$;

int isValidInput$($char $*$input$,$ int $*$x$,$ int $*$y$)$;

int isOccupied$($char board$[$SIZE$][$SIZE$],$ int x$,$ int y$)$;

void drawO$($char board$[$SIZE$][$SIZE$],$ int x$,$ int y$)$;

int main$()\{$

char board$[$SIZE$][$SIZE$]=\{\{\text{'}\text{'},\text{'}\text{'},\text{'}\text{'}\},\{\text{'}\text{'},\text{'}\text{'},\text{'}\text{'}\},\{\text{'}\text{'},\text{'}\text{'},\text{'}\text{'}\}\}$;

char input$[100]$;

int turn $=0$; $//0$ for X$,1$ for O

int x$,$ y;

while $(1)\{$

printBoard$($board$)$;

if $($turn $\%2==0)\{$

printf$("$x$\text{'}$s turn $>")$;

$\}$ else $\{$

printf$("$o$\text{'}$s turn $>")$;

$\}$

if $($fgets$($input$,$ sizeof$($input$),$ stdin$)==$ NULL$)\{$

printf$("$

$")$;

break;

$\}$

if $(!$isValidInput$($input$,$ &x$,$ &y$))\{$

continue;

$\}$

x $-=1$; $//$ Adjust for $0-$based index

y $-=1$; $//$ Adjust for $0-$based index

if $($isOccupied$($board$,$ x$,$ y$))\{$

continue;

$\}$

if $($turn $\%2==0)\{$

board$[$x$][$y$]=\text{'}$X$\text{'}$;

$\}$ else $\{$

drawO$($board$,$ x$,$ y$)$;

$\}$

turn$++$;

if $($turn $==9)\{$

break;

$\}$

$\}$

printBoard$($board$)$;

return $0$;

$\}$

void printBoard$($char board$[$SIZE$][$SIZE$])\{$

int i$,$ j;

for $($i $=0$; i $<$ SIZE; i$++)\{$

for $($j $=0$; j $<$ SIZE; j$++)\{$

printf$("\%$c$",$ board$[$i$][$j$])$;

if $($j $<$ SIZE $-1)$ printf$("|")$;

$\}$

printf$("$

$")$;

if $($i $<$ SIZE $-1)$ printf$("-----$

$")$;

$\}$

$\}$

int isValidInput$($char $*$input$,$ int $*$x$,$ int $*$y$)\{$

int n $=$ sscanf$($input$,"\%$d$,\%$d$",$ x$,$ y$)$;

if $($n $==1)\{$

fprintf$($stderr$,$ "Need $2$ co$-$ordinates

$")$;

return $0$;

$\}$

if $($n $!=2)\{$

fprintf$($stderr$,$ "Illegal character in input $\backslash "\%$s$\backslash "$

$",$ input$)$;

return $0$;

$\}$

if $(*$x $<1||*$x $>3||*$y $<1||*$y $>3)\{$

fprintf$($stderr$,"\%$d$,\%$d is not a valid square; the numbers must be between $1$ and $3$ inclusive

$",*$x$,*$y$)$;

return $0$;

$\}$

return $1$;

$\}$

int isOccupied$($char board$[$SIZE$][$SIZE$],$ int x$,$ int y$)\{$

if $($board$[$x$][$y$]!=\text{'}\text{'})\{$

fprintf$($stderr$,"\%$c has played $\%$d$,\%$d

$",$ board$[$x$][$y$],$ x $+1,$ y $+1)$;

return $1$;

$\}$

return $0$;

$\}$

void drawO$($char board$[$SIZE$][$SIZE$],$ int x$,$ int y$)\{$

board$[$x$][$y$]=\text{'}$O$\text{'}$;

$\}$

PROBLEM: Enhance the tic$-$tac$-$toe game so $2$ people can play. To do this, you need to add an$$O$$ that, like the $$X$,$ is drawn in the square. Then prompt the user for a square identifier, and alternate between drawing $$X$$s and $$O$$s at those locations on the board. The first move is for $$X$.$ You need to detect and reject when a user plays a square that is already taken. Stop after the board is full $($that is$,9$ plays$).$ You do not have to worry about who wins.

The $$O$$ is to be $5\backslash$times $5,$ centered in the middle of the square.

Here are the messages your program should print to the standard output:

The tic$-$tac$-$toe board, with $$X$$s and $$O$$s as appropriate;

When it is $$X$$s turn, print $$X$$s turn $>($note the space after the $>)$; and

When it is $$O$$s turn, print $$O$$s turn $>($again$,$ note the space after the $>).$

Here are the error messages; all are to be printed on the standard error:

When the user enters only $1$ co$-$ordinate: $$Need $2$ co$-$ordinates

$($the $$

$$ is a newline$)$;

When there is an illegal character in the input: $$Illegal character in input $"\%$c$"$

$($the $\%$c$$ is to print the offending character$)$; and

When the square is already occupied: $\%$c has played $\%$d$,\%$d

$($where $\%$c$$ is either $$X$$ or $$O$,$ whichever is already in the square, and $\%$d$,\%$d$$ are the co$-$ordinates of the occupied square$)$; and

When an invalid set of co$-$ordinates are entered: $\%$d$,\%$d$$ is not a valid square; the numbers must be between $1$ and $3$ inclusive

$($each $\%$d is one of the invalid numbers$).$

If the program reads an end of file at the prompt, print a newline and quit.

The program should exit with an exit status code of $0.$