平衡二叉树

//平衡二叉树
#include<stdio.h>
#include<stdlib.h>

struct TreeNode{
	int val;
	int depth;
	TreeNode *left,*right;
};
void computeDepth(TreeNode *root){
	int depth;
	if(root->left!=NULL)
		depth=root->left->depth;
	else
		depth=0;
	if(root->right!=NULL && root->right->depth>depth)
		depth=root->right->depth;
	root->depth=depth+1;
}
TreeNode *balance(TreeNode *root){
	int leftD,rightD;
	TreeNode *newRoot;
	if(root->left!=NULL)
		leftD=root->left->depth;
	else
		leftD=0;
	if(root->right!=NULL)
		rightD=root->right->depth;
	else
		rightD=0;
	if(abs(leftD-rightD)<2)
		return root;
	if(leftD>rightD)
		if(root->left->right!=NULL){
			newRoot=root->left->right;
			root->left->right=newRoot->left;
			newRoot->left=balance(root->left);
			root->left=newRoot->right;
			newRoot->right=balance(root);
		}
		else{
			newRoot=root->left;
			root->left=newRoot->right;
			newRoot->right=root;
		}
	if(leftD<rightD)
		if(root->right->left!=NULL){
			newRoot=root->right->left;
			root->right->left=newRoot->right;
			newRoot->right=balance(root->right);
			root->right=newRoot->left;
			newRoot->left=balance(root);
		}
		else{
			newRoot=root->right;
			root->right=NULL;
			newRoot->left=root;
		}
		computeDepth(newRoot->left);
		computeDepth(newRoot->right);
		return newRoot;
}
TreeNode *insertBTree(TreeNode *root,int val){
	TreeNode *newNode,*newRoot;
	if(root==NULL){
		newNode=new TreeNode;
		newNode->val=val;
		newNode->depth=1;
		newNode->left=NULL;
		newNode->right=NULL;
		return newNode;
	}
	if(val<=root->val)
		root->left=insertBTree(root->left,val);
	else
		root->right=insertBTree(root->right,val);
	newRoot=balance(root);
	computeDepth(newRoot);
	return newRoot;
}
void save_delTree(TreeNode *root,FILE *fout){
	char result[20];
	sprintf(result,"%d
",root->val);
	fputs(result,fout);
	if(root->left!=NULL)
		save_delTree(root->left,fout);
	else
		fputs(" $
",fout);
	if(root->right!=NULL)
		save_delTree(root->right,fout);
	else
		fputs("$
",fout);
	delete root;
}
int main()
{
	FILE *fin,*fout;
	TreeNode *root;
	int val;
	char inFile[30],outFile[30];
	printf("input the data file's name:
");
	scanf("%s",inFile);
	printf("input the file name for saving results:
");
	scanf("%s",outFile);
	root=NULL;
	fin=fopen(inFile,"r");
	while(fscanf(fin,"%d",&val)!=EOF)
		root=insertBTree(root,val);
	fclose(fin);
	fout=fopen(outFile,"w");
	save_delTree(root,fout);
	fclose(fout);
	return 0;
}