c - 树遍历、递归

Question

我想知道下面的代码是如何遍历树的:

//pre order travel 
void travel (BST *tree)
{ 
    the
    if(tree!=NULL)
    {
        printf("%d ",tree->info); 
        travel(tree->left);
        travel(tree->right);
    }
}

我对 travel(tree->left) 和 travel(tree->right) 的递归调用感到困惑。如果我有:

        A
    B       C
  D       E   F

travel(tree->left) 和 travel(tree->right) 如何并排终止遍历树？

Answer 1

我们应用先打印后左后右的顺序:

    A prints goes left


     B prints goes left
        D prints goes left

        D back left goes right

        D back right
     B back left goes right

     B back right

    A back left goes right 

等等……

所以你得到:

A B D C E F