C语言创建以A,B,C,D,E,F,G,H,I,J为节点的二叉树

下面是用C语言创建以A,B,C,D,E,F,G,H,I,J为节点的二叉树的代码：

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

// 定义二叉树节点结构体
typedef struct TreeNode {
    char val;
    struct TreeNode *left;
    struct TreeNode *right;
} TreeNode;

// 创建二叉树
TreeNode* createTree() {
    // 创建节点A
    TreeNode *A = (TreeNode*)malloc(sizeof(TreeNode));
    A->val = 'A';
    // 创建节点B
    TreeNode *B = (TreeNode*)malloc(sizeof(TreeNode));
    B->val = 'B';
    // 创建节点C
    TreeNode *C = (TreeNode*)malloc(sizeof(TreeNode));
    C->val = 'C';
    // 创建节点D
    TreeNode *D = (TreeNode*)malloc(sizeof(TreeNode));
    D->val = 'D';
    // 创建节点E
    TreeNode *E = (TreeNode*)malloc(sizeof(TreeNode));
    E->val = 'E';
    // 创建节点F
    TreeNode *F = (TreeNode*)malloc(sizeof(TreeNode));
    F->val = 'F';
    // 创建节点G
    TreeNode *G = (TreeNode*)malloc(sizeof(TreeNode));
    G->val = 'G';
    // 创建节点H
    TreeNode *H = (TreeNode*)malloc(sizeof(TreeNode));
    H->val = 'H';
    // 创建节点I
    TreeNode *I = (TreeNode*)malloc(sizeof(TreeNode));
    I->val = 'I';
    // 创建节点J
    TreeNode *J = (TreeNode*)malloc(sizeof(TreeNode));
    J->val = 'J';

    // 构建二叉树
    A->left = B;
    A->right = C;
    B->left = D;
    B->right = E;
    C->left = F;
    C->right = G;
    D->left = H;
    D->right = I;
    E->left = J;
    E->right = NULL;
    F->left = NULL;
    F->right = NULL;
    G->left = NULL;
    G->right = NULL;
    H->left = NULL;
    H->right = NULL;
    I->left = NULL;
    I->right = NULL;
    J->left = NULL;
    J->right = NULL;

    return A;
}

// 前序遍历二叉树
void preorderTraversal(TreeNode *root) {
    if (root == NULL) {
        return;
    }
    printf("%c ", root->val);
    preorderTraversal(root->left);
    preorderTraversal(root->right);
}

int main() {
    // 创建二叉树
    TreeNode *root = createTree();
    // 前序遍历二叉树
    printf("前序遍历结果为：");
    preorderTraversal(root);

    return 0;
}

输出结果为：

前序遍历结果为：A B D H I E J C F G