C语言实现二叉树

C语言实现二叉树

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代码

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

struct Node* createnode(long);
struct Node* addnode(long,struct Node*);
void listnodes(struct Node*);
void freenodes(struct Node*);

struct Node{
long item;
int count;
struct Node* pLeft;
struct Node* pRight;
};

/**
 * C语言实现的二叉树结构
 * 原理分析 主要采用递归思想
 */
int main(){
long newvalue=0;
struct Node *pRoot=NULL;
int answer=0;

do{
                printf("enter the node value:\n");
                scanf("%ld",&newvalue);
if(pRoot==NULL)
                        pRoot=createnode(newvalue);
else
                        addnode(newvalue,pRoot);

                printf("do you want to enter another? 0 is yes! 1 is stop!\n");
                scanf("%d",&answer);
        }while((answer==0));


        printf("\nall the input value is:\n");
        listnodes(pRoot);
        freenodes(pRoot);

return 0;
}

struct Node* createnode(long value){
struct Node * pNode=(struct Node *)malloc(sizeof(struct Node));
        pNode->item=value;
        pNode->count=1;
        pNode->pLeft=NULL;
        pNode->pRight=NULL;

return pNode;
}

struct Node* addnode(long value,struct Node*pNode){
if(pNode==NULL)
return createnode(value);

if(pNode->item==value){
                pNode->count++;
return pNode;
        }

if(value<pNode->item){
if(pNode->pLeft==NULL){
                        pNode->pLeft=createnode(value);
return pNode->pLeft;
                }else
return addnode(value,pNode->pLeft);
        }else{
if(pNode->pRight==NULL){
                        pNode->pRight=createnode(value);
return pNode->pRight;
                }else
return addnode(value,pNode->pRight);
        }
}

void listnodes(struct Node*pNode){
if(pNode->pLeft!=NULL)
                listnodes(pNode->pLeft);

for(int i=0;i<pNode->count;i++)
                printf("%ld\n",pNode->item);

if(pNode->pRight!=NULL)
                        listnodes(pNode->pRight);

}

void freenodes(struct Node*pNode){
if(pNode==NULL)
return;

if(pNode->pLeft!=NULL)
                freenodes(pNode->pLeft);

if(pNode->pRight!=NULL)
                freenodes(pNode->pRight);

        free(pNode);
}