CS15二叉树的各种遍历

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1. 上课没听懂折腾了很久所以交晚了
2. 本质上任然是润智师兄的代码，终于弄懂了发现也没这么难，前中后序也折腾出来了，可喜可贺
3. 迭代只能遍历一半（都不到），明天再倒腾

#include<stdio.h>
#include<stdlib.h>
typedef struct _TreeNode{
    int data;
    struct _TreeNode* left;
    struct _TreeNode* right;
} TreeNode;
TreeNode* buildNode(int Data);
void inorder(TreeNode* root);
void before(TreeNode* root);
void after (TreeNode* root);
void  iteration(TreeNode* root);
int main(){
    TreeNode* root = NULL;
    TreeNode* Left = NULL;
    TreeNode* Right = NULL;
    root = buildNode(3);
    Left = buildNode(2);
    Right = buildNode(5);
    root->left = Left;
    root->right = Right;
    TreeNode* LeftLeft = NULL;
    LeftLeft = buildNode(1);
    Left->left = LeftLeft;
    TreeNode* RightRight = NULL;
    RightRight = buildNode(6);
    Right->right = RightRight;
    TreeNode* RightLeft = NULL;
    RightLeft = buildNode(4);
    Right->left = RightLeft;
     iteration(root);
    return 1;
}
TreeNode* buildNode(int Data){
    /* 分配出一个新结点，并用node指针指向它      */
    TreeNode *node = NULL;
    node = (TreeNode*)malloc( sizeof(TreeNode) );
    /*  初始化结点内容   */
    node->data = Data;
    node->left = NULL;
    node->right = NULL;
    /* 将该节点返回  */
    return node;
}
/中序遍历
void inorder(TreeNode* root){
    if( root == NULL )
        return;
    inorder(root->left);            // 先遍历左子树
    printf("%d\n", root->data);     // 访问根结点
    inorder(root->right);            //再遍历右子树
}
前序遍历
void before(TreeNode* root)
{
    if( root == NULL )
        return;
    printf("%d\n", root->data);   //先访问节点
    before(root->left);   //遍历左子树
    before(root->right);          //  再遍历右子树
}
/*后序遍历*/
void after (TreeNode* root)
{
        if( root == NULL )
        return;
        after (root->left);// 后序遍历左子树
        after (root->right);// 后序遍历右子树
    printf("%d\n", root->data);   //   访问节点
}
void  iteration(TreeNode* root)
{
    TreeNode* temp=root->data;
    while(root!=0)
           {
             printf("%d\n", root->data);
             root=root->left;
           }
    root=temp->right;
    {
        printf("%d\n", root->data);
        root=root->right;
    }
}

在此输入正文