为什么添加了一段代码后出现如下报错？

void logo()
{
int i,j;
int logo[5][23]={
{1,1,1,1,0,1,0,0,0,0,1,1,1,1,0,1,0,0,1,0,1,1,1},
{1,0,0,1,0,1,0,0,0,0,1,0,0,1,0,1,0,1,0,0,1,0,0},
{1,1,1,0,0,1,0,0,0,0,1,0,0,1,0,1,1,0,0,0,1,1,1},
{1,0,0,1,0,1,0,0,0,0,1,0,0,1,0,1,0,1,0,0,0,0,1},
{1,1,1,1,0,1,1,1,1,0,1,1,1,1,0,1,0,0,1,0,1,1,1}
};
for(i=0;i<5;i++)
{
for(j=0;j<22;j++)
{
if(logo[i][j])
printf("■");
else
printf(" ");
}
}
}

只有这几行代码么？报错在于你使用的chang_color和gameover没有定义