【C++练习】贪吃蛇

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <ctime>
#include <windows.h>
#include <conio.h>
#define N 28
#define UP 72
#define DOWN 80
#define LEFT 75
#define RIGHT 77
using namespace std;

typedef struct{int x, y;}point;

point snake[400], food, next_head;//next_head pos of head
char game_map

;
int head, tail;
int lv, len, interval;
char dir;

void gotoxy(int x, int y)//prevent blinking
{
HANDLE hConsoleOutput;
COORD dwCursorPosition;
dwCursorPosition.X = x;
dwCursorPosition.Y = y;
hConsoleOutput = GetStdHandle(STD_OUTPUT_HANDLE);
SetConsoleCursorPosition(hConsoleOutput, dwCursorPosition);
}

inline void update(char game_map[]
, int lv, int len, int interval)
{
gotoxy(0, 0);
int i, j;
printf("\n");
for (i = 0; i < N; ++i){
printf("\t\t");
for (j = 0; j < N; ++j)
printf("%c ", game_map[i][j]);
switch(i){
case 0: printf("\tLevel: %d", lv); break;
case 4: printf("\tLength: %d", len); break;
case 8: printf("\tInterval: %3d ms", interval); break;
case 18: printf("\tPress Space to Pause");
}
printf("\n");
}
}

inline void rand_food()
{
srand(int(time(0)));
do{
food.x = rand() % 20 + 1;
food.y = rand() % 20 + 1;
}while (game_map[food.x][food.y] != ' ');
game_map[food.x][food.y] = '$';
}

inline void init()
{
int i, j;
for (i = 1; i <= N-2; ++i)
for (j = 1; j <= N-2; ++j)
game_map[i][j] = ' ';
for (i = 0; i <= N-1; ++i)
game_map[0][i] = game_map[N-1][i] = game_map[i][0] = game_map[i][N-1] = '#';
game_map[1][1] = game_map[1][2] = game_map[1][3] = game_map[1][4] = '@';
game_map[1][5] = 'Q';
head = 4; tail = 0;
snake[head].x = 1; snake[head].y = 5;
snake[tail].x = 1; snake[tail].y = 1;
snake[1].x = 1; snake[1].y = 2;
snake[2].x = 1; snake[2].y = 3;
snake[3].x = 1; snake[3].y = 4;
rand_food();
lv = 0; len = 5; interval = 400;
dir = RIGHT;

puts("\n\n\n\n\n\n\n\n\n\n\n\t\t\t\t\t\tPress Any Key");
getch();
update(game_map, lv, len, interval);
}

inline int mov()
{
bool timeover = true;
double start = (double)clock() / CLOCKS_PER_SEC;            //get total time
char tmp;
here:
//wait for 1s
while ((timeover = ((double)clock() / CLOCKS_PER_SEC - start <= interval / 1000.0)) && !_kbhit());
if (timeover){
char c = getch();
if (c == ' ') {
printf("Game Paused");
while (getch() != ' ');
system("cls");
update(game_map, lv, len, interval);
}
else if ((c != UP && c != DOWN && c != LEFT && c != RIGHT) ||
(dir == UP && c == DOWN) || (dir == DOWN && c == UP) ||
(dir == LEFT && c == RIGHT) || (dir == RIGHT && c == LEFT))
goto here;
else
dir = c;
}
switch (dir){
case UP:
next_head.x = snake[head].x - 1; next_head.y = snake[head].y;
break;
case DOWN:
next_head.x = snake[head].x + 1; next_head.y = snake[head].y;
break;
case LEFT:
next_head.x = snake[head].x; next_head.y = snake[head].y - 1;
break;
case RIGHT:
next_head.x = snake[head].x; next_head.y = snake[head].y + 1;
break;
}
if ((!next_head.x || next_head.x == N-1 || !next_head.y || next_head.y == N-1) ||                       //hit the wall
(game_map[next_head.x][next_head.y] != ' ' && !(next_head.x == food.x && next_head.y == food.y))){   //hit itself
puts("Game Over!\nReplay? y/n");
while (tolower(tmp = getchar()) != 'y' && tolower(tmp) != 'n');
if (tmp == 'y') return 2;
else return 0;
}
if (len == 100){
puts("Congratulations!\nReplay? y/n");
while (tolower(tmp = getchar()) != 'y' && tolower(tmp) != 'n');
if (tmp == 'y') return 2;
else return 0;
}
return 1;
}

inline void eating()
{
++len;
int grade = len / 5 - 1;
if (grade != lv){
lv = grade;
if (interval > 50)
interval = 400 - lv * 50;
}
game_map[next_head.x][next_head.y] = 'Q';                        //change head pos
game_map[snake[head].x][snake[head].y] = '@';        //head becomes body
head = (head + 1) % 400;
snake[head].x = next_head.x;
snake[head].y = next_head.y;                             //change head pos
rand_food();
update(game_map, lv, len, interval);
}

inline void not_eating()
{
game_map[snake[tail].x][snake[tail].y] = ' ';        //tail becomes ' '
tail = (tail + 1) % 400;
game_map[next_head.x][next_head.y] = 'Q';
game_map[snake[head].x][snake[head].y] = '@';
head = (head + 1) % 400;
snake[head].x = next_head.x;
snake[head].y = next_head.y;
update(game_map, lv, len, interval);
}

int main()
{
SetConsoleTitle("Snake");
system("color 3E");
there:
init();
while (1)
switch(mov()){
case 1:
if (next_head.x == food.x && next_head.y == food.y) eating();
else not_eating();
break;
case 2: system("cls"); goto there; break;
default: return 0;
}
return 0;
}