From c4a07b8879878b87f71b065f2df4bb1baa841582 Mon Sep 17 00:00:00 2001
From: Denis Landa <denis.landa@student.tuke.sk>
Date: Fri, 11 Apr 2025 10:20:30 +0200
Subject: [PATCH] 12

---
 du5/snake.c | 104 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 104 insertions(+)
 create mode 100644 du5/snake.c

diff --git a/du5/snake.c b/du5/snake.c
new file mode 100644
index 0000000..a725652
--- /dev/null
+++ b/du5/snake.c
@@ -0,0 +1,104 @@
+#include <stdlib.h>
+#include "snake.h"
+
+struct snake* add_snake(struct snake* snake, int x, int y){
+    struct snake* nova_cast = (struct snake*) calloc(1, sizeof(struct snake));
+    if (nova_cast == NULL){
+        return snake;
+    }
+
+    nova_cast->x = x;
+    nova_cast->y = y;
+    nova_cast->next = snake;
+
+    return nova_cast;
+}
+
+struct snake* remove_snake(struct snake* snake){
+    if (snake == NULL){
+        return NULL;
+    }
+
+    if (snake->next == NULL){
+        free(snake);
+        return NULL;
+    }
+
+    struct snake* predposledny = snake;
+    struct snake* posledny = snake->next;
+
+    while (posledny->next != NULL){
+        predposledny = posledny;
+        posledny = posledny->next;
+    }
+
+    free(posledny);
+    predposledny->next = NULL;
+
+    return snake;
+}
+
+
+int is_snake(struct snake* snake, int x, int y){
+    struct snake* aktualny = snake;
+
+    while (aktualny != NULL){
+        if (aktualny->x == x && aktualny->y == y){
+            return 1;
+        }
+
+        aktualny = aktualny->next;
+    }
+
+    return 0;
+}
+
+void free_snake(struct snake* sn){
+    struct snake* dalsi;
+
+    while (sn != NULL){
+        dalsi = sn->next;
+        free(sn);
+        sn = dalsi;
+    }
+}
+
+int step_state(struct state* state){
+    int nova_pozicia_x = state->snake->x + state->sx;
+    int nova_pozicia_y = state->snake->y + state->sy;
+
+    if (nova_pozicia_x < 0 || nova_pozicia_y < 0 || nova_pozicia_x >= state->width || nova_pozicia_y >= state->height){
+        return END_WALL;
+    }
+
+    if (is_snake(state->snake, nova_pozicia_x, nova_pozicia_y)){
+        return END_SNAKE;
+    }
+
+    for (int i = 0; i < FOOD_COUNT; i++){
+        if (state->foodx[i] == nova_pozicia_x && state->foody[i] == nova_pozicia_y){
+            state->snake = add_snake(state->snake, nova_pozicia_x, nova_pozicia_y);
+            state->foodx[i] = -1;
+            state->foody[i] = -1;
+
+            int este_jedlo = 0;
+            for (int j = 0; j < FOOD_COUNT; j++){
+                if (state->foodx[j] != -1 && state->foody[j] != -1){
+                    este_jedlo = 1;
+                }
+            }
+
+            if (este_jedlo == 0){
+                return END_FOOD;
+            }
+
+            return END_CONTINUE;
+        }
+    }
+
+    state->snake = add_snake(state->snake, nova_pozicia_x, nova_pozicia_y);
+    state->snake = remove_snake(state->snake);
+
+    return END_CONTINUE;
+}
+