请大家帮我看看这个结构体数组嵌套的错误是什么意思
在写俄罗斯方块，这些是在头文件下定义的数据：
是2个结构体的嵌套
///////////////// struct ///////////////////////
typedef struct FK_STATE_TYPE
{
int state[4][4];
}FK_STATE, *FK_STATE_PTR;
typedef struct FK_INFO_TYPE
{
int x,y; //position
FK_STATE fks[4];
}FK_INFO, *FK_INFO_PTR;
extern FK_INFO FK[7];
extern FK_STATE tubian1 = {0,1,0,0,
1,1,1,0,
0,0,0,0,
0,0,0,0};
extern FK_STATE tubian2={0,1,0,0,
0,1,1,0,
0,1,0,0,
0,0,0,0};
extern FK_STATE tubian3={0,0,0,0,
1,1,1,0,
0,1,0,0,
0,0,0,0};
extern FK_STATE tubian4={0,1,0,0,
1,1,0,0,
0,1,0,0,
0,0,0,0};
extern FK_STATE zhengfang1={1,1,0,0,
1,1,0,0,
0,0,0,0,
0,0,0,0};
extern FK_STATE zhengfang2={1,1,0,0,
1,1,0,0,
0,0,0,0,
0,0,0,0};
extern FK_STATE zhengfang3={1,1,0,0,
1,1,0,0,
0,0,0,0,
0,0,0,0};
extern FK_STATE zhengfang4={1,1,0,0,
1,1,0,0,
0,0,0,0,
0,0,0,0};
extern FK_STATE changtiao1={1,0,0,0,
1,0,0,0,
1,0,0,0,
1,0,0,0};
extern FK_STATE changtiao2={0,0,0,0,
1,1,1,1,
0,0,0,0,
0,0,0,0};
extern FK_STATE changtiao3={1,0,0,0,
1,0,0,0,
1,0,0,0,
1,0,0,0};
extern FK_STATE changtiao4={0,0,0,0,
1,1,1,1,
0,0,0,0,
0,0,0,0};
extern FK_STATE youwan1= {1,1,0,0,
1,0,0,0,
1,0,0,0,
0,0,0,0};
extern FK_STATE youwan2={1,1,1,0,
0,0,1,0,
0,0,0,0,
0,0,0,0};
extern FK_STATE youwan3={0,1,0,0,
0,1,0,0,
1,1,0,0,
0,0,0,0};
extern FK_STATE youwan4={1,0,0,0,
1,1,1,0,
0,0,0,0,
0,0,0,0};
extern FK_STATE zuowan1 = {1,1,0,0,
0,1,0,0,
0,1,0,0,
0,0,0,0};
extern FK_STATE zuowan2 = {0,0,1,0,
1,1,1,0,
0,0,0,0,
0,0,0,0};
extern FK_STATE zuowan3 = {1,0,0,0,
1,0,0,0,
1,1,0,0,
0,0,0,0};
extern FK_STATE zuowan4 = {1,1,1,0,
1,0,0,0,
0,0,0,0,
0,0,0,0};
extern FK_STATE youzhe1 = {1,0,0,0,
1,1,0,0,
0,1,0,0,
0,0,0,0};
extern FK_STATE youzhe2 = {0,1,1,0,
1,1,0,0,
0,0,0,0,
0,0,0,0};
extern FK_STATE youzhe3 = {1,0,0,0,
1,1,0,0,
0,1,0,0,
0,0,0,0};
extern FK_STATE youzhe4 = {0,1,1,0,
1,1,0,0,
0,0,0,0,
0,0,0,0};
extern FK_STATE zuozhe1 = {0,1,0,0,
1,1,0,0,
1,0,0,0,
0,0,0,0};
extern FK_STATE zuozhe2 = {1,1,0,0,
0,1,1,0,
0,0,0,0,
0,0,0,0};
extern FK_STATE zuozhe3 = {0,1,0,0,
1,1,0,0,
1,0,0,0,
0,0,0,0};
extern FK_STATE zuozhe4 = {1,1,0,0,
0,1,1,0,
0,0,0,0,
0,0,0,0};
int Init_Block()
{
FK[0].x = 3;
FK[0].y = 0;
FK[0].fks[0] = tubian1;
FK[0].fks[1] = tubian2;
FK[0].fks[2] = tubian3;
FK[0].fks[3] = tubian4;
FK[1].x = 3;
FK[1].y = 0;
FK[1].fks[0] = changtiao1;
FK[1].fks[1] = changtiao2;
FK[1].fks[2] = changtiao3;
FK[1].fks[3] = changtiao4;
FK[2].x = 3;
FK[2].y = 0;
FK[2].fks[0] = zhengfang1;
FK[2].fks[1] = zhengfang2;
FK[2].fks[2] = zhengfang3;
FK[2].fks[3] = zhengfang4;
FK[3].x = 3;
FK[3].y = 0;
FK[3].fks[0] = youwan1;
FK[3].fks[1] = youwan2;
FK[3].fks[2] = youwan2;
FK[3].fks[3] = youwan2;
FK[4].x = 3;
FK[4].y = 0;
FK[4].fks[0] = zuowan1;
FK[4].fks[1] = zuowan2;
FK[4].fks[2] = zuowan3;
FK[4].fks[3] = zuowan4;
FK[5].x = 3;
FK[5].y = 0;
FK[5].fks[0] = youzhe1;
FK[5].fks[1] = youzhe2;
FK[5].fks[2] = youzhe3;
FK[5].fks[3] = youzhe4;
FK[6].x = 3;
FK[6].y = 0;
FK[6].fks[0] = zuozhe1;
FK[6].fks[1] = zuozhe2;
FK[6].fks[2] = zuozhe3;
FK[6].fks[3] = zuozhe4;
return 1;
}
错误语句是：
Compiling...
njde.cpp
Linking...
njde.obj : error LNK2001: unresolved external symbol "struct FK_INFO_TYPE * FK" (?FK@@3PAUFK_INFO_TYPE@@A)
Debug/bjse.exe : fatal error LNK1120: 1 unresolved externals
Error executing link.exe.
bjse.exe - 2 error(s), 0 warning(s)
[解决办法]
extern FK_INFO FK[7]; 去掉extern
[解决办法]
extern FK_INFO FK[7];
表示声明了一个FK_INFO类型的数组，名称为FK，但由于是extern且没有初始化，所以在这里仅仅只是声明，没有定义
