#include <stdio.h>
#include <time.h> 
#include <conio.h> 
#include <windows.h>

void start_game();
void reset_game();
void move_left();
void move_right();
void move_up();
void move_down();

void refresh_show(); 
void add_rand_num(); 
void check_game_over();
int get_null_count(); 

int board[4][4]; 
int score; 
int best; 
int if_need_add_num;
int if_game_over; 

int main()
{
start_game();
}

void start_game()
{
reset_game();
char cmd;
while (1)
{
cmd = getch();

if (if_game_over)
{
if (cmd == 'y' || cmd == 'Y') 
{
reset_game();
continue;
}
else if (cmd == 'n' || cmd == 'N') 
{
return;
}
else
{
continue;
}
}

if_need_add_num = 0; 
switch (cmd) 
{
case 'a':
case 'A':
case 75 :
move_left();
break;
case 's':
case 'S':
case 80 :
move_down();
break;
case 'w':
case 'W':
case 72 :
move_up();
break;
case 'd':
case 'D':
case 77 :
move_right();
break;
} 
score > best ? best = score : 1; 
if (if_need_add_num)
{
add_rand_num();
refresh_show();
}
}
}
void reset_game()
{
score = 0;
if_need_add_num = 1;
if_game_over = 0;
int n = rand() % 16;
for (int i = 0; i < 4; i++)
{
for (int j = 0; j < 4; j++)
{
board[i][j] = (n-- == 0 ? 2 : 0);
}
}
add_rand_num();
system("cls");
refresh_show();
}
void add_rand_num()
{
srand(time(0));
int n = rand() % get_null_count();
for (int i = 0; i < 4; i++)
{
for (int j = 0; j < 4; j++)
{
if (board[i][j] == 0 && n-- == 0) 
{
board[i][j] = (rand() % 3 ? 2 : 4);
return;
}
}
}
}
int get_null_count()
{
int n = 0;
for (int i = 0; i < 4; i++)
{
for (int j = 0; j < 4; j++)
{
board[i][j] == 0 ? n++ : 1;
}
}
return n;
}
void check_game_over()
{
for (int i = 0; i < 4; i++)
{
for (int j = 0; j < 3; j++)
{
if (board[i][j] == board[i][j+1] || board[j][i] == board[j+1][i])
{
if_game_over = 0;
return;
}
}
}
if_game_over = 1;
}
void move_left()
{
for (int i = 0; i < 4; i++)
{
for (int j = 1, k = 0; j < 4; j++)
{
if (board[i][j] > 0) 
{
if (board[i][k] == board[i][j]) 
{
score += board[i][k++] <<= 1;
board[i][j] = 0;
if_need_add_num = 1; 
}
else if (board[i][k] == 0)
{
board[i][k] = board[i][j];
board[i][j] = 0;
if_need_add_num = 1;
}
else 
{
board[i][++k] = board[i][j];
if (j != k)
{
board[i][j] = 0;
if_need_add_num = 1;
}
}
}
}
}
}
void move_right()
{
for (int i = 0; i < 4; i++)
{
for (int j = 2, k = 3; j >= 0; j--)
{
if (board[i][j] > 0)
{
if (board[i][k] == board[i][j])
{
score += board[i][k--] <<= 1;
board[i][j] = 0;
if_need_add_num = 1;
}
else if (board[i][k] == 0)
{
board[i][k] = board[i][j];
board[i][j] = 0;
if_need_add_num = 1;
}
else
{
board[i][--k] = board[i][j];
if (j != k)
{
board[i][j] = 0;
if_need_add_num = 1;
}
}
}
}
}
}
void move_up()
{
for (int i = 0; i < 4; i++)
{
for (int j = 1, k = 0; j < 4; j++)
{
if (board[j][i] > 0)
{
if (board[k][i] == board[j][i])
{
score += board[k++][i] <<= 1;
board[j][i] = 0;
if_need_add_num = 1;
}
else if (board[k][i] == 0)
{
board[k][i] = board[j][i];
board[j][i] = 0;
if_need_add_num = 1;
}
else
{
board[++k][i] = board[j][i];
if (j != k)
{
board[j][i] = 0;
if_need_add_num = 1;
}
}
}
}
}
}
void move_down()
{
for (int i = 0; i < 4; i++)
{
for (int j = 2, k = 3; j >= 0; j--)
{
if (board[j][i] > 0)
{
if (board[k][i] == board[j][i])
{
score += board[k--][i] <<= 1;
board[j][i] = 0;
if_need_add_num = 1;
}
else if (board[k][i] == 0)
{
board[k][i] = board[j][i];
board[j][i] = 0;
if_need_add_num = 1;
}
else
{
board[--k][i] = board[j][i];
if (j != k)
{
board[j][i] = 0;
if_need_add_num = 1;
}
}
}
}
}
}
void refresh_show()
{
COORD pos = {0, 0};
SetConsoleCursorPosition(GetStdHandle(STD_OUTPUT_HANDLE), pos);

printf("\n\n\n\n");
printf(" GAME: 2048 SCORE: %06d BEST: %06d\n", score, best);
printf(" --------------------------------------------------\n\n");
printf(" ┌──┬──┬──┬──┐\n");
for (int i = 0; i < 4; i++)
{
printf(" │");
for (int j = 0; j < 4; j++)
{
if (board[i][j] != 0)
{
if (board[i][j] < 10)
{
printf(" %d │", board[i][j]); 
}
else if (board[i][j] < 100)
{
printf(" %d │", board[i][j]);
}
else if (board[i][j] < 1000)
{
printf(" %d│", board[i][j]);
}
else if (board[i][j] < 10000)
{
printf("%4d│", board[i][j]);
}
else
{
int n = board[i][j];
for (int k = 1; k < 20; k++)
{
n >>= 1;
if (n == 1)
{
printf("2^%02d│", k); 
break;
}
}
}
}
else printf(" │");
}

if (i < 3)
{
printf("\n ├──┼──┼──┼──┤\n");
}
else
{
printf("\n └──┴──┴──┴──┘\n");
}
}

printf("\n");
printf(" --------------------------------------------------\n");
printf(" W↑ A← D→ ↓S");

if (get_null_count() == 0)
{
check_game_over();
if (if_game_over) 
{
printf("\r GAME OVER! TRY THE GAME AGAIN? [Y/N]");
}
}
}