foo.cc:9:1: error: expected initializer before 'void'
9 | void CreatBiTree(BiTree& T)
| ^~~~
foo.cc:25:23: error: variable or field 'PreOrderTraverse' declared void
25 | void PreOrderTraverse(BiTree T)
| ^~~~~~
foo.cc:25:23: error: 'BiTree' was not declared in this scope
foo.cc: In function 'int main()':
foo.cc:36:5: error: 'BiTree' was not declared in this scope
36 | BiTree T;
| ^~~~~~
foo.cc:37:17: error: 'T' was not declared in this scope
37 | CreatBiTree(T);
| ^
foo.cc:37:5: error: 'CreatBiTree' was not declared in this scope
37 | CreatBiTree(T);
| ^~~~~~~~~~~
foo.cc:39:5: error: 'PreOrderTraverse' was not declared in this scope
39 | PreOrderTraverse(T);
| ^~~~~~~~~~~~~~~~
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