refresh

Makefile

@@ -1,6 +1,6 @@
 CC = gcc
 CFLAGS = -Wall -Wextra -std=c99
-dIRS = a1 du1 du2 du3 du4
+dIRS = a1 du1 du2 du3 du4 du5
 all: 
 	@for %%d in ($(dIRS)) do \
 		$(CC) $(CFLAGS) %%d\program.c -o %%d\program.exe

a1/program.c

@@ -13,8 +13,8 @@ void funkcia (int c, int *line_count) {
 }
 
 int main() {
-    int c; //текущий считанный символ
-    int c2 = 0; //счётчик строк
+    int c; 
+    int c2 = 0; 
     while ((c = getchar()) !=EOF) {
         funkcia(c, &c2);
     }

du1/program.c

@@ -11,15 +11,15 @@ int main() {
             break;
         }
             results[count] = num;
-            count++; //нумерация чисел 
+            count++; 
     }
 
-        if (count == 0) { //если не было введено никакое число
+        if (count == 0) { 
             printf("Chyba: Malo platnych hodnot.\n");
             return 0;
     }
 
-            for (int i = 0; i < count; i++) { //выписывание всех чисел 
+            for (int i = 0; i < count; i++) {  
                 printf("Sutaziaci c. %d vypil %d poharov.\n",i+1,results[i]);
             }
 

du2/program.c

@@ -3,17 +3,17 @@
 
 int read_number (double *num) {
     char buffer[50];
-    if (!fgets(buffer, sizeof(buffer), stdin)) { //если fgets не смог считать строку
+    if (!fgets(buffer, sizeof(buffer), stdin)) { 
         return 0;
     }
 
-    if (sscanf(buffer, "%lf", num) != 1) { //переделываем в double. Если всё успешно
+    if (sscanf(buffer, "%lf", num) != 1) { 
         return 0;
     }
     return 1;
 }
 
-double hornerovaschema (double x, double cofecients[], int count) { //вычесляет значение многочлена в точке x
+double hornerovaschema (double x, double cofecients[], int count) { 
     double result = 0.0;
     for (int i = 0; i < count; i++) {
         result = result * x + cofecients[i];
@@ -22,19 +22,19 @@ double hornerovaschema (double x, double cofecients[], int count) { //вычес
 }
 
 int main() {
-    double x; //хранит точку, в которой вычисляется многочлен.
+    double x; 
     double cof[maxcoe];
     int count = 0;
     
-    if (!read_number(&x)) { //если не может считать
+    if (!read_number(&x)) { 
         printf("Nepodarilo sa nacitat zaklad x\n");
         return 0;
     }
 
 
     while (count < maxcoe) {
-        double coef; //переменна для хранения считанного коэффициента
-        char buffer[50];//строковый буфер для fgetc
+        double coef; 
+        char buffer[50];
 
         if (!fgets(buffer, sizeof(buffer), stdin) || buffer[0] == '\n') {
             break;

du5/snake.c

@@ -0,0 +1,43 @@
+#include <stdio.h>
+#include "snake.h"
+#include <stdlib.h>
+
+struct snake* add_snake (struct snake* snake, int x, int y) {
+    struct snake* head = NULL;
+
+    head = malloc(sizeof(struct snake));
+
+    if (!head) {
+        return snake;
+    }    
+        head->x = x;
+        head->y = y;
+
+        head->next = NULL;
+
+        if (snake !=NULL) {
+            head->next = snake;
+        }
+        return head;
+}
+
+struct snake* remove_snake(struct snake* snake) {
+    if(snake == NULL || snake-> next == NULL) {
+        free(snake);
+        return NULL;
+    }
+
+    struct snake* previous = NULL;
+    struct snake* current = NULL;
+    while (current->next !=NULL) {
+        previous = current;
+        current = current->next;
+    }
+
+    if (previous !=NULL) {
+        free(previous->next);
+        previous->next = NULL;
+    }
+}
+
+

du5/snake.h

@@ -0,0 +1,111 @@
+#ifndef snake_h_INCLUDED
+#define snake_h_INCLUDED
+
+// Number of food items on the plane
+#define FOOD_COUNT 5
+
+/**
+ * One part of the snake;
+ * 
+ * The snake is a linked list;
+ */
+struct snake {
+    // x position of the snake part
+    int x;
+    // y position of the snake part
+    int y;
+    // Pointer to the next snake part.
+    // The last part of the snake has NULL pointer to the next part.
+    struct snake* next;
+};
+
+// End game reason constants, return value of step_state
+enum endgame {
+    // Continue the game
+    END_CONTINUE = 0,
+    // Snake hit a wall
+    END_WALL,
+    // Snake hit itself
+    END_SNAKE,
+    // No food left
+    END_FOOD,
+    // Other reason to end
+    END_USER
+};
+
+/**
+ * State of the game.
+ * 
+ * The state consists of the snake, its speed and food on the plane.
+ * 
+ * The snake is a linked list of snake parts.
+ * 
+ * Speed vector is a vector added to the last head position to create a new head.
+ * 
+ * Food are points on the plane. Food with negative coordinates means food is already eaten.
+ */
+struct state {
+    // Snake as a linked list
+    struct snake* snake;
+    // X of the food positions
+    int foodx[FOOD_COUNT];
+    // Y of the food positions
+    int foody[FOOD_COUNT];
+    int sx;
+    int sy;
+    int width;
+    int height;
+};
+
+/**
+ * Add a new snake part with given position. The new snake part becomes the new head.
+ *
+ * @param head of the snake.
+ * @param x coordinate of the new head;
+ * @param y coordinate of the new head.
+ * @return new head of the snake.
+ */
+struct snake* add_snake(struct snake* snake, int x, int y);
+
+/**
+ * Remove the last snake part.
+ * The last snake part  should always have NULL next pointer.
+ *
+ * @param head of the snake.
+ * @return new head of the snake.
+ */
+struct snake* remove_snake(struct snake* snake);
+
+/**
+ * Finds out if given coordinates are part of the snake.
+ * @param snake
+ * @param x coordinate to search in snake
+ * @param y coordinate to search in snake
+ * @return True, if there is a snake part with coordinates x,y. False otherwise
+ */
+int is_snake(struct snake* snake, int x, int y);
+
+/**
+ * Remove and free each snake part;
+ * @param head of the snake.
+ */
+void free_snake(struct snake* sn);
+
+/**
+ * Change game state.
+ *
+ * The function should calculate new position of the snake head
+ * from the current position and speed vector.
+ * Then it should modify snake parts or food coordinates according to the rules:
+ * 
+ * - If the new position is on the snake, end the game, return END_SNAKE.
+ * - If the new position is on the food, mark food as eaten
+ *   (set its coordinates to -1) and add new snake part on the position of the food. If there is no food left, return END_FOOD. Else return END_CONTINUE.
+ * - If the new position is on the plane, add new snake part on the new position and remove the last part of the snake, return END_CONTINUE.
+ * 
+ * @param current state of the game
+ * @return reason to end the game according to enum endgame.
+ */
+int step_state(struct state* state);
+
+#endif // snake_h_INCLUDED