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\n",root->val);
fputs(result,fout);
if(root->left!=NULL)
save_delTree(root->left,fout);
else
fputs(" $\n",fout);
if(root->right!=NULL)
save_delTree(root->right,fout);
else
fputs("$\n",fout);
delete root;
}
int main()
{
FILE *fin,*fout;
TreeNode *root;
int val;
char inFile[30],outFile[30];
printf("input the data file's name:\n");
scanf("%s",inFile);
printf("input the file name for saving results:\n");
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;
}