二叉排序树BST代码（JAVA）

publicclassTest{

publicstaticvoidmain(String[]args){

int[]r=newint[]{5,1,3,4,6,7,2,8,9,0};

BSTbinarySearchTree=newBST(r);

binarySearchTree.inOrder();

System.out.println();

binarySearchTree.searchBST(6);//查找成功

System.out.println();

binarySearchTree.searchBST(10);//查找失败->插入

System.out.println();

}

}

publicclassBST{

//二叉树结点

publicclassBiNode{

intdata;

BiNodeleft;

BiNoderight;

BiNode(intdata,BiNodeleft,BiNoderight){

this.data=data;

this.left=left;

this.right=right;

}

}

privateBiNoderoot=null;

BST(int[]r)

{

for(inti=0;i<r.length;i++)

{

BiNodes=newBiNode(r[i],null,null);

root=insertBST(root,s);

//insertBST1(s);

}

}

//插入（递归）

publicBiNodeinsertBST(BiNodehead,BiNodes)

{

if(head==null){

head=s;

returnhead;

}

if(s.data<head.data)

head.left=insertBST(head.left,s);

else

head.right=insertBST(head.right,s);

returnhead;

}

//插入（非递归：循环、用临时变量保存过程）

publicvoidinsertBST1(BiNodes)

{

if(root==null){

root=s;

return;

}

BiNodetemp=root;//需要临时结点记录

while(true)

{

if(s.data<temp.data)

{

if(temp.left==null)

{

temp.left=s;

return;

}

temp=temp.left;

}

else

{

if(temp.right==null)

{

temp.right=s;

return;

}

temp=temp.right;

}

}

}

//查找：成功->返回；失败：插入

publicBiNodesearchBST(inta)

{

BiNodes1=searchBST(root,a);

if(s1==null){

BiNodes2=newBiNode(a,null,null);

insertBST1(s2);

System.out.println("searchfail;insertsuccess:"+s2.data);

inOrder();

returns2;

}else{

System.out.println("searchsuccess:"+s1.data);

returns1;

}

}

//查找

privateBiNodesearchBST(BiNodehead,inta)

{

if(head==null)

returnnull;

if(a<head.data)

returnsearchBST(head.left,a);

elseif(a>head.data)

returnsearchBST(head.right,a);

else

returnhead;

}

//删除

//删除f的孩子p

publicvoiddeleteLeftBST(BiNodef,BiNodep)

{

if(p.left==null&&p.right==null)//p为叶子

{

f.left=null;

p=null;

}

elseif(p.right==null)//p只有左子树

{

f.left=p.left;

p=null;

}

elseif(p.left==null)//p只有右子树

{

f.left=p.right;

p=null;

}

else//p的左右子树均不空

{

BiNodepar=p,s=par.right;//用pars去查找p的右子树的最左下结点

while(s.left!=null)

{

par=s;

s=par.left;

}

p.data=s.data;//交换最左下结点s与p结点数据

//剪枝（删除s结点）

if(par==p)//处理特殊情况

{

par.right=s.right;

s=null;

}

else//处理一般情况

{

par.left=s.right;

s=null;

}

}

}

//先序遍历

publicvoidpreOrder(){

System.out.print("preOrdertraversalwithrecursion:");

preOrder(root);

System.out.println();

}

//递归

privatevoidpreOrder(BiNoderoot){

if(root==null)return;

System.out.print(root.data);//访问结点

preOrder(root.left);

preOrder(root.right);

}

//中序遍历

publicvoidinOrder(){

System.out.print("inOrdertraversalwithrecursion:");

inOrder(root);

System.out.println();

}

//递归

privatevoidinOrder(BiNoderoot){

if(root==null)//访问结点

return;

inOrder(root.left);

System.out.print(root.data);//访问结点

inOrder(root.right);

}

//后序遍历

publicvoidpostOrder(){

System.out.print("postOrdertraversalwithrecursion:");

postOrder(root);

System.out.println();

}

//递归

privatevoidpostOrder(BiNoderoot){

if(root==null)return;

postOrder(root.left);

postOrder(root.right);

System.out.print(root.data);//访问结点

}

}

inOrdertraversalwithrecursion:0123456789

searchsuccess:6

searchfail;insertsuccess:10

inOrdertraversalwithrecursion:012345678910