From 5ec0f07e6fcac1a88144c835673cbc1f4d7dbb73 Mon Sep 17 00:00:00 2001
From: Anzhelika Nikolaieva <anzhelika.nikolaieva@student.tuke.sk>
Date: Thu, 13 Apr 2023 13:50:39 +0000
Subject: [PATCH] Update 'du7/snake.c'

---
 du7/snake.c | 85 +++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 83 insertions(+), 2 deletions(-)

diff --git a/du7/snake.c b/du7/snake.c
index 7038cdb..7535d1a 100644
--- a/du7/snake.c
+++ b/du7/snake.c
@@ -2,22 +2,103 @@
 #include <stdlib.h>
 
 struct snake* add_snake(struct snake* snake,int x,int y){
-    return NULL;
+    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){
-    return NULL;
+   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 = snake;
+        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 (new_head_x < 0 || new_head_x >= state->width || new_head_y < 0 || new_head_y >= state->height) {
+        return END_WALL;
+    }
+
+    // Check if snake hit itself
+    if (is_snake(state->snake, new_head_x, new_head_y)) {
+        return END_SNAKE;
+    }
+
+    // Check if snake ate food
+    int food_eaten = 0;
+    for (int i = 0; i < FOOD_COUNT; i++) {
+        if (state->foodx[i] >= 0 && state->foodx[i] == new_head_x && state->foody[i] == new_head_y) {
+            state->foodx[i] = -1;
+            state->foody[i] = -1;
+            state->snake = add_snake(state->snake, new_head_x, new_head_y);
+            food_eaten = 1;
+            break;
+        }
+    }
+
+    // Check if game ended
+    if (!food_eaten) {
+        int food_left = 0;
+        for (int i = 0; i < FOOD_COUNT; i++) {
+            if (state->foodx[i] >= 0) {
+                food_left = 1;
+                break;
+            }
+        }
+        if (!food_left) {
+            return END_FOOD;
+        }
+        // Remove the last snake part
+        state->snake = remove_snake(state->snake);
+        // Add new snake part
+        state->snake = add_snake(state->snake, new_head_x, new_head_y);
+    }
+
     return END_CONTINUE;
 }
+