View Compilation Error

0_0_21493657_7606.cpp: In function 'void Preorder2(BiTree)':
0_0_21493657_7606.cpp:36:18: error: 'struct BiNode' has no member named 'child'
             p=p->child;
                  ^
0_0_21493657_7606.cpp:42:18: error: 'struct BiNode' has no member named 'child'
             p=p->child;
                  ^
0_0_21493657_7606.cpp: In function 'void Inorder(BiTree)':
0_0_21493657_7606.cpp:60:14: error: void value not ignored as it ought to be
             p=q.pop();
              ^