pvjc23/du7/snake.c

105 lines
2.3 KiB
C

#include "snake.h"
#include <stdlib.h>
struct snake* add_snake(struct snake* snake,int x,int y){
struct snake* new_head = (struct snake*) malloc(sizeof(struct snake));
new_head->x = x;
new_head->y = y;
new_head->next = snake;
return new_head;
}
struct snake* remove_snake(struct snake* snake){
if (snake == NULL) {
return NULL;
}
struct snake* current = snake;
struct snake* p = NULL;
while (current->next != NULL) {
p = current;
current = current->next;
}
free(current);
if (p == NULL) {
return NULL;
}
p->next = NULL;
return snake;
}
void free_snake(struct snake* sn){
struct snake* current = sn;
while (current != NULL) {
struct snake* next = current->next;
free(current);
current = next;
}
}
int is_snake(struct snake* snake,int x,int y){
struct snake* current = snake;
while (current != NULL) {
if (current->x == x && current->y == y) {
return 1;
}
current = current->next;
}
return 0;
}
int step_state(struct state* st){
int nx = (st->snake->x + st->sx);
int ny = (st->snake->y + st->sy);
if (nx < 0 || nx >= st->width || ny < 0 || ny >= st->height) {
return END_WALL;
}
// Check if snake hit itself
if (is_snake(st->snake, nx, ny)) {
return END_SNAKE;
}
// Check if snake ate food
int food_eaten = 0;
for (int i = 0; i < FOOD_COUNT; i++) {
if (st->foodx[i] >= 0 && st->foodx[i] == nx && st->foody[i] == ny) {
st->foodx[i] = -1;
st->foody[i] = -1;
st->snake = add_snake(st->snake, nx, ny);
food_eaten = 1;
break;
}
}
// Check if game ended
if (!food_eaten) {
int food_left = 0;
for (int i = 0; i < FOOD_COUNT; i++) {
if (st->foodx[i] >= 0) {
food_left = 1;
break;
}
}
if (!food_left) {
return END_FOOD;
}
// Remove the last snake part
st->snake = remove_snake(st->snake);
// Add new snake part
st->snake = add_snake(st->snake, nx, ny);
}
return END_CONTINUE;
}