用c语言编写一个二叉树

以下是一个简单的二叉树的C语言实现，包括插入、删除和查找节点的基本操作。

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

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

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

void insertNode(TreeNode** root, int val) {
    if (*root == NULL) {
        *root = createNode(val);
        return;
    }
    if (val < (*root)->val) {
        insertNode(&((*root)->left), val);
    } else if (val > (*root)->val) {
        insertNode(&((*root)->right), val);
    }
}

TreeNode* findNode(TreeNode* root, int val) {
    if (root == NULL || root->val == val) {
        return root;
    }
    if (val < root->val) {
        return findNode(root->left, val);
    } else {
        return findNode(root->right, val);
    }
}

TreeNode* findMinNode(TreeNode* root) {
    while (root->left != NULL) {
        root = root->left;
    }
    return root;
}

void deleteNode(TreeNode** root, int val) {
    if (*root == NULL) {
        return;
    }
    if (val < (*root)->val) {
        deleteNode(&((*root)->left), val);
    } else if (val > (*root)->val) {
        deleteNode(&((*root)->right), val);
    } else {
        if ((*root)->left == NULL && (*root)->right == NULL) {
            free(*root);
            *root = NULL;
        } else if ((*root)->left == NULL) {
            TreeNode* temp = *root;
            *root = (*root)->right;
            free(temp);
        } else if ((*root)->right == NULL) {
            TreeNode* temp = *root;
            *root = (*root)->left;
            free(temp);
        } else {
            TreeNode* minNode = findMinNode((*root)->right);
            (*root)->val = minNode->val;
            deleteNode(&((*root)->right), minNode->val);
        }
    }
}

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

int main() {
    TreeNode* root = NULL;
    insertNode(&root, 5);
    insertNode(&root, 3);
    insertNode(&root, 7);
    insertNode(&root, 1);
    insertNode(&root, 4);
    insertNode(&root, 6);
    insertNode(&root, 8);
    printf("Original tree: ");
    printTree(root);
    printf("\n");
    deleteNode(&root, 1);
    printf("After deleting 1: ");
    printTree(root);
    printf("\n");
    deleteNode(&root, 7);
    printf("After deleting 7: ");
    printTree(root);
    printf("\n");
    deleteNode(&root, 5);
    printf("After deleting 5: ");
    printTree(root);
    printf("\n");
    return 0;
}

该程序的输出如下：

Original tree: 1 3 4 5 6 7 8 
After deleting 1: 3 4 5 6 7 8 
After deleting 7: 3 4 5 6 8 
After deleting 5: 3 4 6 8 

该二叉树示例中包含了插入节点、查找节点、删除节点和打印二叉树的基本操作。可以根据需要进行修改和扩展。