Defining the correct struct based on existing code - c

Question

I've got some homework troubles with C struct… if anyone can be helpful. Because I don't get it.
The working code contains those bits (It's a game with a snake that has a head containing a direction):
game_t *game = …;
game->snake.head->direction = …;
snake_info(game->snake)
snake_destroy(&(game->snake));
The prototypes (I apparently cannot change):
void snake_info(snake_t const *snake);
void snake_destroy(snake_t *snake);
And the structure I'm trying to build.
typedef struct game {
snake_t snake; // to match call to snake_destroy and direction assignation
// or
snake_t *snake; // to match call to snake_info
} game_t;
But I cannot get both to work at the same time.
EDIT: the struct was called snake while it's actually game.
Do I miss something obvious or is there a problem with those prototypes (or calls)?
EDIT 2:
Compiler error with the first solution snake_t snake (in game):
snake.c: In function ‘game_print’:
snake.c:244:5: erreur: incompatible type for argument 1 of ‘snake_info’
gamecore.c:20:6: note: expected ‘const struct snake_t *’ but argument is of type ‘snake_t’
Compiler error with the second solution ̀ snake_t *snake`:
snake.c: In function ‘game_destroy’:
snake.c:205:5: attention : passing argument 1 of ‘snake_destroy’ from incompatible pointer type
gamecore.c:54:6: note: expected ‘struct snake_t *’ but argument is of type ‘struct snake_t **’

Answer 1

Your struct is incorrect. You have two members both with the same name 'snake'
Both must have unique names within the scope of the struct to permit legal code

Answer 2

The compiler error says it all, you have to define your struct using struct snake_t:
typedef struct game {
struct snake_t snake;
} game_t;
You have to use snake_t snake because of snake.head within the given code.

Answer 3

There is a bit of confusion with where pointers are used. With more practice using pointers will become more natural to you.
Also, use variable names that do not conflict with the names of structures.
Depending upon how much pointer usage you want in your code.
Minimal edits to existing code:
typedef struct game {
snake_t snake; // A snake_t instance is created with the game instance..
} game_t;
--
game_t *game = …;
game->snake.head->direction = …;
// snake_info requires a snake_t reference so pass the address of game->snake
//snake_info(game->snake);
snake_info(&(game->snake));
snake_destroy(&(game->snake));
Minimal pointers:
typedef struct game {
snake_t snake; // A snake_t instance is created with the game instance..
} game_t;
--
// Use a game_t variable instead of a pointer
//game_t *game = …;
game_t aGame = …; // renamed variable to avoid conflicts
// change the snake.head to snake->head since the game object uses a snake_t pointer
// game->snake.head->direction = …;
aGame.snake.head->direction = …;
// Pass the address of aGame.snake
snake_info(&(aGame.snake));
// this line is okay since you pass the address of game->snake.
snake_destroy(&(aGame.snake));
Making more use of pointers:
typedef struct game {
snake_t *snake; // A pointer to a snake_t instance.
} game_t;
--
// Create a game_t instance
game_t aGame = …;
// Create a snake_t instance
snake_t aSnake = ... ;
// Create a game_t pointer and assign it the address of aGame
game_t *aGamePtr = &aGame;
// Using aGamePtr, assign the snake variable in aGame the address of aSnake
aGamePtr->snake = &aSnake;
// Since the game_t object is a snake_t pointer,
// change the snake.head to snake->head
// game->snake.head->direction = …;
aGamePtr->snake->head->direction = …;
// this line is okay since aGamePtr->snake is a pointer.
snake_info(aGamePtr->snake);
// Since game object uses a snake_t pointer, pass aGamePtr->snake directly
// snake_destroy(&(game->snake));
snake_destroy(aGamePtr->snake);