From d4d57c03445ac0f79f5e0e563859ce5bfc6f5b10 Mon Sep 17 00:00:00 2001
From: Rudolf Zambory <rudolf.zambory@student.tuke.sk>
Date: Wed, 9 Apr 2025 11:12:51 +0200
Subject: [PATCH] sssssssss

---
 du5/snake.c | 81 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 81 insertions(+)
 create mode 100644 du5/snake.c

diff --git a/du5/snake.c b/du5/snake.c
new file mode 100644
index 0000000..b3d08d5
--- /dev/null
+++ b/du5/snake.c
@@ -0,0 +1,81 @@
+#include <stdlib.h>
+#include "snake.h"
+
+struct snake* add_snake(struct snake* head, int x, int y) {
+    struct snake* new_head = (struct snake*)calloc(1, sizeof(struct snake));
+    new_head->x = x;
+    new_head->y = y;
+    new_head->next = head;
+    return new_head;
+}
+
+struct snake* remove_snake(struct snake* head) {
+    if (head == NULL) return NULL;
+
+    struct snake* current = head;
+    struct snake* previous = NULL;
+
+    while (current->next != NULL) {
+        previous = current;
+        current = current->next;
+    }
+
+    free(current);
+    if (previous != NULL) {
+        previous->next = NULL;
+    } else {
+        return NULL;
+    }
+    return head;
+}
+
+int is_snake(struct snake* head, int x, int y) {
+    struct snake* current = head;
+    while (current != NULL) {
+        if (current->x == x && current->y == y) {
+            return 1;
+        }
+        current = current->next;
+    }
+    return 0;
+}
+
+void free_snake(struct snake* head) {
+    struct snake* current = head;
+    while (current != NULL) {
+        struct snake* next = current->next;
+        free(current);
+        current = next;
+    }
+}
+
+int step_state(struct state* state) {
+    int new_x = state->snake->x + state->sx;
+    int new_y = state->snake->y + state->sy;
+
+    if (new_x < 0 || new_x >= state->width || new_y < 0 || new_y >= state->height) {
+        return END_WALL;
+    }
+
+    if (is_snake(state->snake, new_x, new_y)) {
+        return END_SNAKE;
+    }
+
+    for (int i = 0; i < FOOD_COUNT; i++) {
+        if (state->foodx[i] == new_x && state->foody[i] == new_y) {
+            state->foodx[i] = -1;
+            state->foody[i] = -1;
+            state->snake = add_snake(state->snake, new_x, new_y);
+            for (int j = 0; j < FOOD_COUNT; j++) {
+                if (state->foodx[j] != -1) {
+                    return END_CONTINUE;
+                }
+            }
+            return END_FOOD;
+        }
+    }
+
+    state->snake = add_snake(state->snake, new_x, new_y);
+    state->snake = remove_snake(state->snake);
+    return END_CONTINUE;
+}