From bf9c2bf8c625f3639e2b17302f1871340bad2337 Mon Sep 17 00:00:00 2001
From: Filip Chochol <filip.chochol@student.tuke.sk>
Date: Fri, 8 May 2026 11:13:41 +0200
Subject: [PATCH] game

---
 du4/game.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 du4/game.h | 36 ++++++++++++++++++++++++++++++++
 2 files changed, 97 insertions(+)
 create mode 100644 du4/game.c
 create mode 100644 du4/game.h

diff --git a/du4/game.c b/du4/game.c
new file mode 100644
index 0000000..6f05ef5
--- /dev/null
+++ b/du4/game.c
@@ -0,0 +1,61 @@
+#include "snake.h"
+#include <stdlib.h>
+
+struct snake* add_snake(struct snake* snake, int x, int y) {
+    struct snake* novy_uzol = calloc(1, sizeof(struct snake));
+    novy_uzol->x = x;
+    novy_uzol->y = y;
+    novy_uzol->next = snake;
+    return novy_uzol;
+}
+
+struct snake* remove_snake(struct snake* hlava) {
+    if (hlava == NULL) return NULL;
+    if (hlava->next == NULL) {
+        free(hlava);
+        return NULL;
+    }
+    hlava->next = remove_snake(hlava->next);
+    return hlava;
+}
+
+int is_snake(struct snake* snake, int x, int y) {
+    for (struct snake* clanok = snake; clanok != NULL; clanok = clanok->next) {
+        if (clanok->x == x && clanok->y == y) return 1;
+    }
+    return 0;
+}
+
+void free_snake(struct snake* sn) {
+    if (sn == NULL) return;
+    free_snake(sn->next);
+    free(sn);
+}
+
+int step_state(struct state* st) {
+    int next_x = st->snake->x + st->sx;
+    int next_y = st->snake->y + st->sy;
+
+    if (next_x < 0 || next_x >= st->width || next_y < 0 || next_y >= st->height)
+        return END_WALL;
+
+    for (int i = 0; i < FOOD_COUNT; i++) {
+        if (st->foodx[i] == next_x && st->foody[i] == next_y) {
+            st->foodx[i] = -1;
+            st->foody[i] = -1;
+            st->snake = add_snake(st->snake, next_x, next_y);
+            int zostava_jedlo = 0;
+            for (int j = 0; j < FOOD_COUNT; j++) {
+                if (st->foodx[j] >= 0) zostava_jedlo = 1;
+            }
+            if (!zostava_jedlo) return END_FOOD;
+            return END_CONTINUE;
+        }
+    }
+
+    st->snake = remove_snake(st->snake);
+    if (is_snake(st->snake, next_x, next_y))
+        return END_SNAKE;
+    st->snake = add_snake(st->snake, next_x, next_y);
+    return END_CONTINUE;
+}
diff --git a/du4/game.h b/du4/game.h
new file mode 100644
index 0000000..bde2cbb
--- /dev/null
+++ b/du4/game.h
@@ -0,0 +1,36 @@
+#ifndef snake_h_INCLUDED
+#define snake_h_INCLUDED
+
+#define FOOD_COUNT 20
+
+struct snake {
+    int x;
+    int y;
+    struct snake* next;
+};
+
+enum endgame {
+    END_CONTINUE = 0,
+    END_WALL,
+    END_SNAKE,
+    END_FOOD,
+    END_USER
+};
+
+struct state {
+    struct snake* snake;
+    int foodx[FOOD_COUNT];
+    int foody[FOOD_COUNT];
+    int sx;
+    int sy;
+    int width;
+    int height;
+};
+
+struct snake* add_snake(struct snake* snake, int x, int y);
+struct snake* remove_snake(struct snake* snake);
+int is_snake(struct snake* snake, int x, int y);
+void free_snake(struct snake* sn);
+int step_state(struct state* state);
+
+#endif