先根遍历二叉树c语言程序,二叉树先序遍历C语言实现

以下是二叉树的先序遍历C语言实现：

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

struct node {
    int data;
    struct node *left;
    struct node *right;
};

void preorder(struct node *root) {
    if (root == NULL) {
        return;
    }
    printf("%d ", root->data);
    preorder(root->left);
    preorder(root->right);
}

int main() {
    struct node *root = (struct node*)malloc(sizeof(struct node));
    root->data = 1;
    root->left = (struct node*)malloc(sizeof(struct node));
    root->left->data = 2;
    root->left->left = NULL;
    root->left->right = NULL;
    root->right = (struct node*)malloc(sizeof(struct node));
    root->right->data = 3;
    root->right->left = (struct node*)malloc(sizeof(struct node));
    root->right->left->data = 4;
    root->right->left->left = NULL;
    root->right->left->right = NULL;
    root->right->right = (struct node*)malloc(sizeof(struct node));
    root->right->right->data = 5;
    root->right->right->left = NULL;
    root->right->right->right = NULL;

    printf("先序遍历结果为：");
    preorder(root);
    printf("\n");

    return 0;
}

上述代码中，我们定义了一个二叉树的结构体，包含数据、左子节点和右子节点。然后，我们定义了一个先序遍历的函数，其中先访问根节点、再遍历左子树、最后遍历右子树。在主函数中，我们手动构造了一棵二叉树，并输出它的先序遍历结果。