6-1 Depth of Binary Tree* (10 points)

The node structure of a known binary tree is defined as follows:

typedef struct  NODE
{
    int data;
    struct  NODE  *lch, *rch;
} NODE;

Description: data It is a data field. lch and are  rch pointers to the left and right children, respectively.

Please write a function to find the depth of a binary tree.

function prototype

int Depth(const NODE *root);

Description: root It is the root pointer of the binary tree, and the function value is the depth of the binary tree.

referee procedure

int main()
{
    NODE *root;
    Create(&root);
    Input(&root);
    printf("%d\n", Depth(root));
    printf("%d\n", Depth(root));
    Destroy(&root);
    return 0;
}

Explanation: The Create function creates an empty binary tree, and the Destroy function destroys the binary tree. The Input function inputs the binary tree in root-first traversal order, and the node values ​​are all positive integers, and zero is input when an empty tree is encountered.

input sample

85 37 94 53 0 0 21 0 0 0 18 46 0 60 0 0 9 0 72 0 0

output sample

4
4

 

int Depth(const NODE *root)
{
    int dep1, dep2;
    if (root == NULL)
        return 0;
    else
    {
        dep1 = Depth(root->lch);//递归调用左子树
        dep2 = Depth(root->rch);//递归调用右子树
        return dep1 > dep2 ? dep1 + 1 : dep2 + 1;
        //返回两者中最大的值
    }
}