Tic-Tac-Toe游戏的C语言二维数组为什么出错**

Tic-Tac-Toe游戏的C语言二维数组为什么出错*

第一个错误：8 22 I:\C语言学习文件\学习\Tic-tac-toe游戏网上版.cpp [Error] use of parameter outside function body before ‘]’ token
第二个错误：35 22 I:\C语言学习文件\学习\Tic-tac-toe游戏网上版.cpp [Error] ‘num’ was not declared in this scope

第三个错误：40 8 I:\C语言学习文件\学习\Tic-tac-toe游戏网上版.cpp [Error] ‘a’ was not declared in this scope

#include 

/*Tic-Tac-Toe游戏，主函数输入一个棋盘规模大小，
然后接着输入目前棋盘的形态，
然后调用judge函数，判断游戏是否结束的简单小游戏程序。
主要考察二维数组和标记变量的知识点。*/

int judge(int num,int a[num][num]); //函数声明 

int main(void){
	int num;  //棋盘的大小
	while (scanf("%d", &num) != EOF)   //这是什么判断？ 
	{
		
		int a[num][num];               //输入棋盘内的数字 
		for(int i=0; i

8 28 I:\C语言学习文件\学习\Tic-tac-toe游戏网上版.cpp [Error] use of parameter outside function body before ‘]’ token
8 33 I:\C语言学习文件\学习\Tic-tac-toe游戏网上版.cpp [Error] use of parameter outside function body before ‘]’ token
32 28 I:\C语言学习文件\学习\Tic-tac-toe游戏网上版.cpp [Error] use of parameter outside function body before ‘]’ token
32 33 I:\C语言学习文件\学习\Tic-tac-toe游戏网上版.cpp [Error] use of parameter outside function body before ‘]’ token
I:\C语言学习文件\学习\Tic-tac-toe游戏网上版.cpp In function ‘int judge(…)’:
35 22 I:\C语言学习文件\学习\Tic-tac-toe游戏网上版.cpp [Error] ‘num’ was not declared in this scope
40 8 I:\C语言学习文件\学习\Tic-tac-toe游戏网上版.cpp [Error] ‘a’ was not declared in this scope
53 23 I:\C语言学习文件\学习\Tic-tac-toe游戏网上版.cpp [Error] ‘num’ was not declared in this scope
58 9 I:\C语言学习文件\学习\Tic-tac-toe游戏网上版.cpp [Error] ‘a’ was not declared in this scope
74 19 I:\C语言学习文件\学习\Tic-tac-toe游戏网上版.cpp [Error] ‘num’ was not declared in this scope
76 8 I:\C语言学习文件\学习\Tic-tac-toe游戏网上版.cpp [Error] ‘a’ was not declared in this scope
82 12 I:\C语言学习文件\学习\Tic-tac-toe游戏网上版.cpp [Error] ‘num’ was not declared in this scope
90 19 I:\C语言学习文件\学习\Tic-tac-toe游戏网上版.cpp [Error] ‘num’ was not declared in this scope
92 8 I:\C语言学习文件\学习\Tic-tac-toe游戏网上版.cpp [Error] ‘a’ was not declared in this scope
98 12 I:\C语言学习文件\学习\Tic-tac-toe游戏网上版.cpp [Error] ‘num’ was not declared in this scope

a 和num 在函数声明中都定义了int 类型了呀
为什么还会出错**