재 귀적 인 이 진 트 리 기반 옮 겨 다 니 기

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

struct TreeNode{
	int val;
	TreeNode *left,*right;
};
TreeNode *insertTree(TreeNode *root,int val){  
    TreeNode *newNode;  
    if(root==NULL){  
        newNode=new TreeNode;  
        newNode->val=val;  
        newNode->left=NULL;  
        newNode->right=NULL;  
        return newNode;  
    }  
    if(val<=root->val)  
        root->left=insertTree(root->left,val);  
    else  
        root->right=insertTree(root->right,val);  
    return root;  
}  
void delTree(TreeNode *root){  
    if(root->left!=NULL)  
        delTree(root->left);  
    if(root->right!=NULL)  
        delTree(root->right);  
    delete root;  
}  
void LFRTraverse(TreeNode *root){
	if(root->left!=NULL)
		LFRTraverse(root->left);
	printf("%d-",root->val);
	if(root->right!=NULL)
		LFRTraverse(root->right);
}
void FLRTraverse(TreeNode *root){
	printf("%d-",root->val);
	if(root->left!=NULL)
		FLRTraverse(root->left);
	if(root->right!=NULL)
		FLRTraverse(root->right);
}
int main()
{
	FILE *fin;
	TreeNode *root;
	int val;
	char inFile[30];
	printf("input the data file's name:
");
	scanf("%s",inFile);
	fin=fopen(inFile,"r");
	root=NULL;
	while(fscanf(fin,"%d",&val)!=EOF)
		root=insertTree(root,val);
	fclose(fin);
	printf("traversing left sub-tree firstly,then root,and right sub-tree lastly:
");
	LFRTraverse(root);
	printf("
");
	printf("traversing root firstly,then left sub-tree,and right sub-tree lastly:
");
	FLRTraverse(root);
	printf("
");
	delTree(root);
	return 0;
}