Обновить du5/snake.c

du5/snake.c

@@ -2,17 +2,51 @@
 #include <stdlib.h>
 
 struct snake* add_snake(struct snake* snake, int x, int y) {
-    return NULL;
+    struct snake* head = calloc(1, sizeof(struct snake));
+    if (head == NULL) {
+        return NULL; // Handle memory allocation failure
+    }
+    head->x = x;
+    head->y = y;
+    head->next = snake;
+    return head;
 }
 
 struct snake* remove_snake(struct snake* snake) {
+    if (snake == NULL) {
+        return NULL;
+    }
+    if (snake->next == NULL) {
+        free(snake);
         return NULL;
     }
 
+    struct snake* this = snake;
+    struct snake* prev = NULL;
+    while (this->next != NULL) {
+        prev = this;
+        this = this->next;
+    }
+
+    free(this);
+    prev->next = NULL;
+    return snake;
+}
+
 void free_snake(struct snake* sn) {
+    if (sn == NULL) {
+        return;
+    }
+    free_snake(sn->next);
+    free(sn);
 }
 
 int is_snake(struct snake* snake, int x, int y) {
+    for (struct snake* this = snake; this != NULL; this = this->next) {
+        if (this->x == x && this->y == y) {
+            return 1;
+        }
+    }
     return 0;
 }