以下是用c语言写的贪吃蛇的代码，我想知道这段代码哪段用了数据结构的知识，又用了哪些数据解耦的知识

以下是代码：

#include <stdio.h>
#include <stdlib.h>
#include <conio.h>
#include <windows.h>
#include <time.h>

#define MAXSIZE 1000

typedef struct node{
    int x;
    int y;
}Node;

typedef struct snake{
    Node body[MAXSIZE];
    int length;
    int direction;
}Snake;

Node food;
int score;

void init(Snake *snake)
{
    int i;
    snake -> length = 3;
    snake -> direction = 77;
    for(i = 0; i < snake -> length; i++){
        snake -> body[i].x = 20 - i;
        snake -> body[i].y = 20;
    }
    srand(time(NULL));
    food.x = rand() % 38 + 1;
    food.y = rand() % 18 + 1;
    score = 0;
}

void draw(Snake *snake)
{
    int i;
    system("cls");
    printf("score:%d\n\n", score);
    for(i = 0; i < snake -> length; i++){
        printf("@");
        if(i == snake -> length - 1){
            printf(">");
        }
    }
    printf("\n\n");
    for(i = 0; i < 20; i++){
        printf("#                    #\n");
    }
    for(i = 0; i < snake -> length; i++){
        gotoxy(snake -> body[i].x, snake -> body[i].y);
        printf("*");
    }
    gotoxy(food.x, food.y);
    printf("$");
}

void updateWithoutInput(Snake *snake)
{
    int i;
    for(i = 0; i < snake -> length - 1; i++){
        snake -> body[i] = snake -> body[i + 1];
    }
    switch(snake -> direction){
        case 75:snake -> body[snake -> length - 1].x--;break;
        case 77:snake -> body[snake -> length - 1].x++;break;
        case 72:snake -> body[snake -> length - 1].y--;break;
        case 80:snake -> body[snake -> length - 1].y++;break;
    }
    if(snake -> body[snake -> length - 1].x == food.x && snake -> body[snake -> length - 1].y == food.y){
        snake -> length++;
        score += 10;
        food.x = rand() % 38 + 1;
        food.y = rand() % 18 + 1;
    }
}

void updateWithInput(Snake *snake)
{
    char input;
    if(kbhit()){
        input = getch();
        switch(input){
            case 75:
            case 80:
            case 77:
            case 72:
                if(abs(snake -> direction - input) != 2){
                    snake -> direction = input;
                }
                break;
            default:break;
        }
    }
    updateWithoutInput(snake);
}

int check(Snake *snake)
{
    int i;
    if(snake -> body[snake -> length - 1].x == 0 || snake -> body[snake -> length - 1].x == 39 || snake -> body[snake -> length - 1].y == 0 || snake -> body[snake -> length - 1].y == 19){
        return 1;
    }
    for(i = 0; i < snake -> length - 1; i++){
        if(snake -> body[snake -> length - 1].x == snake -> body[i].x && snake -> body[snake -> length - 1].y == snake -> body[i].y){
            return 1;
        }
    }
    return 0;
}

int main()
{
    Snake snake;
    init(&snake);
    while(1){
        draw(&snake);
        Sleep(200);
        updateWithInput(&snake);
        if(check(&snake) == 1){
            printf("\n\n\n\n\n\n\n\n\n\n                    Game over!\n\n");
            system("pause");
            return 0;
        }
    }
    return 0;
}

这段代码用了如下的数据结构：

1. 链表：通过定义Node结构体，把每个节点的坐标定义为Node结构体的成员，从而形成一个链表，表示蛇的身体；

2. 结构体：通过定义Snake结构体，把蛇的身体和方向等信息封装在一起，方便处理；

这段代码用了如下的数据解耦的知识：

1. 模块化编程：通过定义多个函数，把不同的功能模块分离开来，使得代码结构更加清晰，易于维护和扩展；

2. 抽象化：通过把蛇的身体和方向等信息封装在Snake结构体中，把食物的坐标封装在food结构体中，使得代码更加简洁，易于理解。