数据结构二叉树后序遍历 C语言

野性酷女 2023-02-18 03:18 6阅读 0赞

**二叉树的遍历：是指从根节点出发，按照某种次序依次访问二叉树中的所有结点。**

**二叉树遍历一共又有四种：  
1.前序遍历  
2.后序遍历  
3.中序遍历  
4.层序遍历**

口诀：

后序：左右根

后序遍历：若树为空，则空操作返回，否则从左到右先叶子后结点的方式访问遍历左右子树，最后访问根节点。  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDE3NDMxMg_size_16_color_FFFFFF_t_70_pic_center]  
后序遍历结果：H I D J E B K F G C A  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDE3NDMxMg_size_16_color_FFFFFF_t_70_pic_center 1]后序遍历：8 6 7 5

#include <stdio.h>
    #include <stdlib.h>
    typedef struct node{
        
      int data;
      struct node* left; 
      struct node* right;
    } Node;
    //先序遍历
    void preorder(Node* node){
        
      if(node !=NULL){
        
        printf("%d",node -> data);
        preorder(node -> left);
           printf("%d",node -> data);
        preorder(node -> right);
      }
      }
      //中序遍历 
    void inorder(Node* node)
    {
        
    if(node!=NULL){
        
       inorder(node -> left);
       printf("%d\n",node ->data);
       inorder (node -> right);
    }
    }
    //后序遍历 
    void postorder(Node* node){
        
    if(node!=NULL){
        
    postorder(node ->left);
    postorder(node ->right);
    printf("%d\n",node ->data);
    }
    }
    
    
    
    int main(){
        
    Node n1;
    Node n2;
    Node n3;
    Node n4;
    n1.data = 5;
    n2.data=6;
    n3.data =7;
    n4.data=8;
    n1.left = &n2;
    n1.right = &n3;
    n2.left =&n4;
    n2.right=NULL;
    n3.left =NULL;
    n3.right =NULL;
    n4.left=NULL;
    n4. right=NULL;
    
    postorder(&n1);
    }

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDE3NDMxMg_size_16_color_FFFFFF_t_70_pic_center 2]

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