c语言代码实现二叉链表作为存储结构，输入键值序列建立一棵二叉排序树，然后中序遍历这棵二叉树。

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

typedef struct _node {
    int key;
    struct _node* left;
    struct _node* right;
} Node;

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

void insert(Node** root, int key) {
    if (*root == NULL) {
        *root = create_node(key);
        return;
    }
    if (key < (*root)->key) {
        insert(&((*root)->left), key);
    } else {
        insert(&((*root)->right), key);
    }
}

void inorder_traversal(Node* root) {
    if (root == NULL) {
        return;
    }
    inorder_traversal(root->left);
    printf("%d ", root->key);
    inorder_traversal(root->right);
}

int main() {
    Node* root = NULL;
    int n, key;
    printf("Enter the number of keys: ");
    scanf("%d", &n);
    printf("Enter the keys: ");
    for (int i = 0; i < n; i++) {
        scanf("%d", &key);
        insert(&root, key);
    }
    printf("Inorder traversal: ");
    inorder_traversal(root);
    printf("\n");
    return 0;
}

输入示例：

Enter the number of keys: 7
Enter the keys: 3 1 4 1 5 9 2

输出示例：

Inorder traversal: 1 1 2 3 4 5 9