java语言实现二叉排序树的操作

public class BiSearchTree {

private BiTree root;

public static void main(String[] args) {

BiSearchTree bst = new BiSearchTree();

bst.root = new BiTree(null, null, 45);

bst.insert(bst.root, 24);

bst.insert(bst.root, 53);

bst.insert(bst.root, 12);

bst.insert(bst.root, 90);

bst.insert(bst.root, 30);

bst.insert(bst.root, 25);

System.out.println("构造完成后：");

System.out.println("中序遍历序列为：");

bst.inTraverse(bst.root);

System.out.println();

System.out.println("前序遍历序列为：");

bst.preTraverse(bst.root);

System.out.println();

System.out.println("查找的数据元素为：" + bst.find(bst.root, 24).data);

System.out.println("删除节点45后：");

bst.delete(bst.root, 45);

System.out.println("中序遍历序列为：");

bst.inTraverse(bst.root);

System.out.println();

System.out.println("前序遍历序列为：");

bst.preTraverse(bst.root);

}

public BiTree find(BiTree root, int key) {

if(root == null)return null;

else if(root.data == key)return root;

else if(root.data > key) return find(root.lchild, key);

else return find(root.rchild, key);

}

public void insert(BiTree root, int key) {

if(key < root.data) {

if(root.lchild == null) {

BiTree p = new BiTree(null, null, key);

root.lchild = p;

}

else insert(root.lchild, key);

}

else if(key > root.data) {

if(root.rchild == null) {

BiTree p = new BiTree(null, null, key);

root.rchild = p;

}

else insert(root.rchild, key);

}

return;

}

//分三种情况：左孩子为空，右孩子为空，左右孩子都为空

//当左右孩子都为空时，将被删除节点的左分支节点的最大节点（即左孩子的最右边孩子）复制到被删除节点

public void delete(BiTree root, int key) {

if(root == null)return;

else if(key == root.data) {

if(root.lchild==null) {

root = root.rchild;

}

else if(root.rchild==null) {

root = root.lchild;

}

else{

//q为s的双亲

//s为左孩子的最右边孩子，将其值赋值给被删除节点

BiTree s = root.lchild;

BiTree q = root;

while(s.rchild != null){

q = s;

s = s.rchild;

}

root.data = s.data;

if(q == root) root.lchild = s.lchild;

else q.rchild = s.lchild;

}

}

else if(key < root.data) {

delete(root.lchild, key);

}

else{

delete(root.rchild, key);

}

}

public void inTraverse(BiTree root) {

if(root != null) {

inTraverse(root.lchild);

System.out.print(root.data + " ");

inTraverse(root.rchild);

}

}

public void preTraverse(BiTree root) {

if(root != null) {

System.out.print(root.data + " ");

preTraverse(root.lchild);

preTraverse(root.rchild);

}

}

}

class BiTree {

public BiTree lchild;

public BiTree rchild;

public int data;

public BiTree(BiTree lchild, BiTree rchild, int data) {

super();

this.lchild = lchild;

this.rchild = rchild;

this.data = data;

}

}