c语言编程实现二叉树的基本运算（包括查找、插入、删除节点等）以及”二叉树与树的相互转换 点击复制后，将打开C知道体验页”，并提供可供程序(包括基本运算)测试的界面

以下是实现二叉树基本运算（查找、插入、删除节点）的C语言代码，同时包括了二叉树与树的相互转换：

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

/* 二叉树节点结构体 */
struct TreeNode {
    int val;
    struct TreeNode *left;
    struct TreeNode *right;
};

/* 插入节点 */
struct TreeNode* insert(struct TreeNode* root, int val) {
    if (root == NULL) {
        root = (struct TreeNode*)malloc(sizeof(struct TreeNode));
        root->val = val;
        root->left = NULL;
        root->right = NULL;
    } else if (val < root->val) {
        root->left = insert(root->left, val);
    } else if (val > root->val) {
        root->right = insert(root->right, val);
    }
    return root;
}

/* 查找节点 */
struct TreeNode* search(struct TreeNode* root, int val) {
    if (root == NULL || root->val == val) {
        return root;
    } else if (val < root->val) {
        return search(root->left, val);
    } else {
        return search(root->right, val);
    }
}

/* 删除节点 */
struct TreeNode* delete(struct TreeNode* root, int val) {
    if (root == NULL) {
        return root;
    } else if (val < root->val) {
        root->left = delete(root->left, val);
    } else if (val > root->val) {
        root->right = delete(root->right, val);
    } else {
        /* 找到要删除的节点 */
        if (root->left == NULL) {
            /* 只有右子树或没有子树 */
            struct TreeNode* temp = root->right;
            free(root);
            return temp;
        } else if (root->right == NULL) {
            /* 只有左子树 */
            struct TreeNode* temp = root->left;
            free(root);
            return temp;
        } else {
            /* 左右子树都存在 */
            struct TreeNode* temp = root->right;
            while (temp->left != NULL) {
                temp = temp->left;
            }
            root->val = temp->val;
            root->right = delete(root->right, temp->val);
        }
    }
    return root;
}

/* 打印二叉树 */
void printTree(struct TreeNode* root, int level) {
    if (root != NULL) {
        printTree(root->right, level + 1);
        for (int i = 0; i < level; i++) {
            printf("    ");
        }
        printf("%d\n", root->val);
        printTree(root->left, level + 1);
    }
}

/* 节点结构体 */
struct Node {
    int val;
    struct Node* children;
    struct Node* sibling;
};

/* 将二叉树转换为树 */
struct Node* convertToTree(struct TreeNode* root) {
    if (root == NULL) {
        return NULL;
    }
    struct Node* node = (struct Node*)malloc(sizeof(struct Node));
    node->val = root->val;
    node->children = convertToTree(root->left);
    node->sibling = convertToTree(root->right);
    return node;
}

/* 将树转换为二叉树 */
struct TreeNode* convertToBinaryTree(struct Node* root) {
    if (root == NULL) {
        return NULL;
    }
    struct TreeNode* node = (struct TreeNode*)malloc(sizeof(struct TreeNode));
    node->val = root->val;
    node->left = convertToBinaryTree(root->children);
    node->right = convertToBinaryTree(root->sibling);
    return node;
}

int main() {
    struct TreeNode* root = NULL;
    int choice = 0;
    int val = 0;
    while (1) {
        printf("1. 插入节点\n");
        printf("2. 查找节点\n");
        printf("3. 删除节点\n");
        printf("4. 打印二叉树\n");
        printf("5. 将二叉树转换为树\n");
        printf("6. 将树转换为二叉树\n");
        printf("7. 退出程序\n");
        printf("请输入选项：");
        scanf("%d", &choice);
        switch (choice) {
            case 1:
                printf("请输入要插入的节点值：");
                scanf("%d", &val);
                root = insert(root, val);
                break;
            case 2:
                printf("请输入要查找的节点值：");
                scanf("%d", &val);
                if (search(root, val) != NULL) {
                    printf("节点存在\n");
                } else {
                    printf("节点不存在\n");
                }
                break;
            case 3:
                printf("请输入要删除的节点值：");
                scanf("%d", &val);
                root = delete(root, val);
                break;
            case 4:
                printTree(root, 0);
                break;
            case 5:
                struct Node* tree = convertToTree(root);
                printf("树的结构：\n");
                printf("%d\n", tree->val);
                printf("    %d\n", tree->children->val);
                printf("        %d\n", tree->children->children->val);
                printf("    %d\n", tree->children->sibling->val);
                printf("        %d\n", tree->children->sibling->children->val);
                break;
            case 6:
                struct TreeNode* binaryTree = convertToBinaryTree(root);
                printf("二叉树结构：\n");
                printTree(binaryTree, 0);
                break;
            case 7:
                exit(0);
            default:
                printf("输入有误，请重新输入\n");
                break;
        }
    }
    return 0;
}

程序的测试界面比较简单，用户可以通过选择菜单选项来进行二叉树的基本操作，同时也可以转换为树或者树转换为二叉树。界面上会根据用户的操作实时输出二叉树的结构。