写一个c语言代码按先序遍历序列根据外部输入建立一个二叉树的二叉链表，统计二叉树中叶子结点个数和二叉树的深度。

#include <stdio.h>
#include <stdlib.h>

typedef struct Node {
    int data;
    struct Node *left;
    struct Node *right;
} Node;

Node *createNode(int data) {
    Node *node = (Node *)malloc(sizeof(Node));
    node->data = data;
    node->left = NULL;
    node->right = NULL;
    return node;
}

Node *buildTree(int preorder[], int *index, int min, int max, int size) {
    if (*index >= size) {
        return NULL;
    }
    int val = preorder[*index];
    if (val < min || val > max) {
        return NULL;
    }
    Node *node = createNode(val);
    (*index)++;
    node->left = buildTree(preorder, index, min, val, size);
    node->right = buildTree(preorder, index, val, max, size);
    return node;
}

int countLeaves(Node *root) {
    if (root == NULL) {
        return 0;
    }
    if (root->left == NULL && root->right == NULL) {
        return 1;
    }
    return countLeaves(root->left) + countLeaves(root->right);
}

int maxDepth(Node *root) {
    if (root == NULL) {
        return 0;
    }
    int leftDepth = maxDepth(root->left);
    int rightDepth = maxDepth(root->right);
    return 1 + (leftDepth > rightDepth ? leftDepth : rightDepth);
}

int main() {
    int preorder[] = {5, 3, 1, 4, 7, 6, 8};
    int size = sizeof(preorder) / sizeof(preorder[0]);
    int index = 0;
    Node *root = buildTree(preorder, &index, 0, 10000, size);
    int leaves = countLeaves(root);
    int depth = maxDepth(root);
    printf("Leaves: %d\n", leaves);
    printf("Depth: %d\n", depth);
    return 0;
}

这里以先序遍历序列为例，根据外部输入建立二叉树。函数 `buildTree` 递归地建立二叉树，每次将序列中的第一个元素作为当前节点的值，然后继续递归建立左右子树。 `countLeaves` 和 `maxDepth` 分别用于统计二叉树的叶子结点个数和深度。