没有与这些操作数匹配的"[]"运算符

问题遇到的现象和发生背景

小游戏贪吃蛇，

问题相关代码，请勿粘贴截图

#include <graphics.h>
#include <stdio.h>
#include <conio.h>       
#include <stdlib.h>
#include <time.h>         
#include <string>
#include <Windows.h>
#include <iostream>
#include <math.h>
#include <istream>
using std::cin;
using std::cout;

struct pos_xy
{
    //坐标
    int x;
    int y;
};
struct snakeInfo
{
    int num;                     //蛇的节数 
    struct pos_xy xy{ 100 };    //蛇的最大节数是100节
     char position;               //蛇的方向
}snake;

struct foodInfo
{
    struct pos_xy xy;             //蛇的坐标
    int flag;                     //蛇的标记
    int grade;                    //蛇自带的经验值
}food;
enum snakePosition{right,left,down,up};

void initSnake()
{
    snake.xy[2].x = 0;
    snake.xy[2].y = 0;

    snake.xy[1].x = 10;
    snake.xy[1].y = 0;

    snake.xy[0].x = 20;
    snake.xy[0].y = 0;

    snake.num = 3;
    snake.position = left;           //蛇的初始方向

    food.grade = 0;
}
void drawSnake()
{
    for (int i = 0; i < snake.num; i++)
    {
        setfillcolor(RED);
        fillrectangle(snake.xy.x, snake.xy.y, snake.xy.x + 10, snake.xy.y + 10);

    }

};
void moveSnake()
{
    for (int i = snake.num - 1; i > 0; i--)
    {
        snake.xy.x = snake.xy.x;
        snake.xy.y = snake.xy.y;
    }
    switch (snake.position)
    {
    case right:
        snake.xy.x -= 10;
        break;
    case left:
        snake.xy.x += 10;
        break;
    case down:
        snake.xy.y += 10;
        break;
    case up:
        snake.xy.y -= 10;
        break;
    }
}
void keyDown()
{
    char ch = 0;
    ch = _getch();
    switch(ch)
    {
    case 'w':
    case 'W':
    case 72:
        if (snake.position != down) 
        {
            snake.position = up;
        }
        break;
    case 's':
    case 'S':
    case 80:
        if (snake.position != up) 
        {
            snake.position = down;
        }
        break;
    case 'a':
    case 'A':
    case 75:
        if (snake.position != left)
        {
            snake.position = right;
        }
        break;
    case 'd':
    case 'D':
    case 77:
        if (snake.position != right)
        {
            snake.position = left;
        }
        break;
    }
}
void initFood() 
{
    srand((unsigned int)time(NULL));

    food.xy.x = rand() % 80 * 10;
    food.xy.y = rand() % 60 * 10;
    food.flag = 1;

    for (int i = 0;i < snake.num;i++)
    {
        if (food.xy.x == snake.xy.x && food.xy.y == snake.xy.y)
        {
            food.xy.x = rand() % 80 * 10;
            food.xy.y = rand() % 60 * 10;
        }
    }
}
void drawFood()
{
    fillrectangle(food.xy.x, food.xy.y, food.xy.x + 10, food.xy.y + 10);
}
void eatFood()
{
    if (snake.xy.x == food.xy.x && snake.xy.y == food.xy.y)
    {
        snake.num++;
        food.grade += 10;
        food.flag = 0;
    }
}

int main()
{
    initgraph(900, 600);
    setbkcolor(WHITE);
    cleardevice();
    initSnake();

    while (1)
    {
        cleardevice();
        if (food.flag == 0)
        {
            initFood;
        }
        drawFood();
        drawSnake();
        moveSnake();
        eatFood();
        if (_kbhit())
        {
            keyDown();
        }
        Sleep(50);
    }



    cout << "游戏结束！！！！";




    closegraph();
    return 0;
}

运行结果及报错内容

无法运行，错误E0349

void initSnake()
{
    snake.xy[2].x = 0;
    snake.xy[2].y = 0;

    snake.xy[1].x = 10;
    snake.xy[1].y = 0;

    snake.xy[0].x = 20;
    snake.xy[0].y = 0;

    snake.num = 3;
    snake.position = left;           //蛇的初始方向

    food.grade = 0;
}

此处的六个"[]"都出现了错误提示

我的解答思路和尝试过的方法

我想要达到的结果

贪吃蛇 cmd命令行
https://juejin.cn/user/2595295089934200
贪吃蛇 easyX

贪吃蛇 easyX版 - 掘金 ![image.png](https://p9-juejin.byteimg.com/tos-cn-i-k3u1fbpfcp/7f2c3af47843402ea8cbb2136bc67245~tplv https://juejin.cn/post/7028370274512797709

xy是个结构变量，不是数组啊
struct pos_xy xy{ 100 }; //蛇的最大节数是100节
改为 struct pos_xy xy[100];