du4

du4/game.c

@@ -0,0 +1,90 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include "game.h"
+
+struct snake* add_snake(struct snake* s, int x, int y) {
+    struct snake* n = malloc(sizeof(struct snake));
+    n->x = x; n->y = y; n->next = s;
+    return n;
+}
+
+struct snake* remove_snake(struct snake* s) {
+    if (!s || !s->next) { if (s) free(s); return NULL; }
+    struct snake* curr = s;
+    while (curr->next->next) curr = curr->next;
+    free(curr->next);
+    curr->next = NULL;
+    return s;
+}
+
+int is_snake(struct snake* s, int x, int y) {
+    for (; s; s = s->next) if (s->x == x && s->y == y) return 1;
+    return 0;
+}
+
+void free_snake(struct snake* s) {
+    while (s) { struct snake* t = s; s = s->next; free(t); }
+}
+
+int step_state(struct state* s) {
+    int nx = s->snake->x + s->sx;
+    int ny = s->snake->y + s->sy;
+
+    if (nx < 0 || nx >= s->width || ny < 0 || ny >= s->height) return END_WALL;
+    if (is_snake(s->snake, nx, ny)) return END_SNAKE;
+
+    for (int i = 0; i < FOOD_COUNT; i++) {
+        if (s->foodx[i] == nx && s->foody[i] == ny) {
+            s->foodx[i] = -1; s->foody[i] = -1;
+            s->snake = add_snake(s->snake, nx, ny);
+            for (int j = 0; j < FOOD_COUNT; j++) if (s->foodx[j] >= 0) return END_CONTINUE;
+            return END_FOOD;
+        }
+    }
+
+    s->snake = add_snake(s->snake, nx, ny);
+    s->snake = remove_snake(s->snake);
+    return END_CONTINUE;
+}
+
+void draw(struct state* s) {
+    printf("\033[H\033[J");
+    for (int y = 0; y < s->height; y++) {
+        for (int x = 0; x < s->width; x++) {
+            if (s->snake->x == x && s->snake->y == y) printf("O");
+            else if (is_snake(s->snake->next, x, y)) printf("o");
+            else {
+                int f = 0;
+                for (int i = 0; i < FOOD_COUNT; i++) 
+                    if (s->foodx[i] == x && s->foody[i] == y) { printf("*"); f = 1; break; }
+                if (!f) printf(".");
+            }
+        }
+        printf("\n");
+    }
+    printf("Controls: w/a/s/d + Enter. Quit: q\n");
+}
+
+int main() {
+    struct state s = {NULL, {2, 5, 10, 15, 18}, {2, 8, 3, 7, 1}, 1, 0, 20, 10};
+    s.snake = add_snake(NULL, 10, 5);
+    int res = END_CONTINUE;
+    char c;
+
+    while (res == END_CONTINUE) {
+        draw(&s);
+        if (scanf(" %c", &c) != 1 || c == 'q') break;
+        if (c == 'w') { s.sx = 0; s.sy = -1; }
+        else if (c == 's') { s.sx = 0; s.sy = 1; }
+        else if (c == 'a') { s.sx = -1; s.sy = 0; }
+        else if (c == 'd') { s.sx = 1; s.sy = 0; }
+        res = step_state(&s);
+    }
+
+    if (res == END_WALL) printf("Game Over: Wall hit!\n");
+    else if (res == END_SNAKE) printf("Game Over: Self bite!\n");
+    else if (res == END_FOOD) printf("Victory: All food eaten!\n");
+
+    free_snake(s.snake);
+    return 0;
+}

du4/game.h

@@ -0,0 +1,36 @@
+#ifndef game_h_INCLUDED
+#define game_h_INCLUDED
+
+#define FOOD_COUNT 5
+
+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