二叉树中序遍历c语言代码

二叉树中序遍历的 C 语言代码如下：

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

struct TreeNode {
    int val;
    struct TreeNode *left;
    struct TreeNode *right;
};

void inorderTraversal(struct TreeNode* root){
    if(root == NULL) return;
    inorderTraversal(root->left);
    printf("%d ", root->val);
    inorderTraversal(root->right);
}

int main() {
    // 创建一棵二叉树
    struct TreeNode* root = (struct TreeNode*)malloc(sizeof(struct TreeNode));
    root->val = 1;
    root->left = (struct TreeNode*)malloc(sizeof(struct TreeNode));
    root->left->val = 2;
    root->left->left = NULL;
    root->left->right = NULL;
    root->right = (struct TreeNode*)malloc(sizeof(struct TreeNode));
    root->right->val = 3;
    root->right->left = NULL;
    root->right->right = NULL;

    // 中序遍历二叉树
    inorderTraversal(root);

    return 0;
}

输出结果为：`2 1 3`，即为二叉树的中序遍历结果。