#include

#include

#include

#include

#include

using namespace std;

vector$>$ board $=\{\{0,0,0\},$

$\{0,0,0\},$

$\{0,0,0\}\}$;

unordered$\_$set usedNumbers;

void displayBoard$()\{$

for $($const auto& row : board$)\{$

for $($int value : row$)\{$

cout $<<$ value $<<""$;

$\}$

cout $<<$ endl;

$\}$

$\}$

bool checkWin$()\{$

$//$ Check rows and columns

for $($int i $=0$; i $<3$; $++$i$)\{$

int rowSum $=0$;

int colSum $=0$;

for $($int j $=0$; j $<3$; $++$j$)\{$

rowSum $+=$ board$[$i$][$j$]$;

colSum $+=$ board$[$j$][$i$]$;

$\}$

if $($rowSum $==15||$ colSum $==15)$

return true;

$\}$

$//$ Check diagonals

int diag$1=$ board$[0][0]+$ board$[1][1]+$ board$[2][2]$;

int diag$2=$ board$[0][2]+$ board$[1][1]+$ board$[2][0]$;

if $($diag$1==15||$ diag$2==15)$

return true;

return false;

$\}$

bool boardFull$()\{$

for $($const auto& row : board$)\{$

for $($int value : row$)\{$

if $($value $==0)$

return false;

$\}$

$\}$

return true;

$\}$

void userMove$($bool playEven$)\{$

char rowLetter;

int value;

bool validInput $=$ false;

while $(!$validInput$)\{$

cout $<<$ "Your turn $($Enter the position $($a$-$i$)$ and value$)$: $"$;

cin $>>$ rowLetter $>>$ value;

if $($usedNumbers$.$count$($value$)>0||$ rowLetter $<\text{'}$a$\text{'}||$ rowLetter $>\text{'}$i$\text{'}||$ value $<1||$ value $>9||($playEven && value $\%2==0)||(!$playEven && value $\%2!=0))\{$

cout $<<$ "Invalid move. Please try again." $<<$ endl;

$\}$ else $\{$

int row $=($rowLetter $-\text{'}$a$\text{'})/3$;

int col $=($rowLetter $-\text{'}$a$\text{'})\%3$;

if $($board$[$row$][$col$]!=0)\{$

cout $<<$ "Spot already occupied. Please try again." $<<$ endl;

$\}$ else $\{$

board$[$row$][$col$]=$ value;

usedNumbers.insert$($value$)$;

validInput $=$ true;

$\}$

$\}$

$\}$

$\}$

void computerMove$($bool playEven$)\{$

int value;

bool validMove $=$ false;

while $(!$validMove$)\{$

value $=$ rand$()\%9+1$; $//$ Random number between $1$ and $9$

if $($usedNumbers$.$count$($value$)==0$ && $(($playEven && value $\%2==0)||(!$playEven && value $\%2!=0)))\{$

int row, col;

do $\{$

row $=$ rand$()\%3$;

col $=$ rand$()\%3$;

$\}$ while $($board$[$row$][$col$]!=0)$;

board$[$row$][$col$]=$ value;

usedNumbers.insert$($value$)$;

validMove $=$ true;

$\}$

$\}$

$\}$

int main$()\{$

srand$($time$(0))$;

cout $<<$ "Welcome to the Sum$-$Up$-15$ Game!" $<<$ endl;

char playerChoice;

cout $<<"$Do you want to play with even numbers? $($y$/$n$)$: $"$;

cin $>>$ playerChoice;

bool playEven $=($playerChoice $==\text{'}$y$\text{'}||$ playerChoice $==\text{'}$Y$\text{'})$;

bool userTurn $=$ true;

while $($true$)\{$

$//$ Player's turn

if $($userTurn$)\{$

displayBoard$()$;

userMove$(!$playEven$)$; $//$ If playEven is true, user should play odd numbers, and vice versa

if $($checkWin$())\{$

cout $<<$ "Congratulations! You win!" $<<$ endl;

break;

$\}$

$\}$ else $\{//$ Computer's turn

computerMove$(!$playEven$)$; $//$ If playEven is true, computer should play odd numbers, and vice versa

if $($checkWin$())\{$

cout $<<$ "Computer wins! Better luck next time." $<<$ endl;

break;

$\}$

$\}$

if $($boardFull$())\{$

cout $<<$ "It's a draw!" $<<$ endl;

break;

$\}$

userTurn $=!$userTurn;

$\}$

displayBoard$()$;

return $0$;

$\}$

modify this code by adding an AI algorith so that the code plays the best move rather than a random move. you can use stuufs like minimax algorithm. C$++$