本文实例讲述了java实现二叉树的建立、计算高度与递归输出操作。分享给大家供大家参考，具体如下：

1. 建立 递归输出 计算高度 前中后三种非递归输出

public class tree_link {

private int save = 0;

private int now = 0;

scanner sc = new scanner(system.in);

/*

* 构造函数

*/

tree_link(){

}

/*

* 链表建立

*/

public tree link_build(tree head){

// tree head = new tree();//头节点

system.out.println("继续code：1");

int flag = sc.nextint();

if(flag != 1){

return head;

}else{

system.out.println("\n\n\n输入 节点信息：");

head.setcode(sc.nextint());

system.out.println("\n建立 左 子树code：1 否则：0");

flag = sc.nextint();

if(flag == 1){

now++;

tree ltree = new tree();

head.setltree(ltree);

ltree.setfronttree(head);//设置父母节点

link_build( head.getltree() );

}

system.out.println("\n当前位置：" + head.getcode());

system.out.println("\n建立 右 子树code：1 否则：0");

flag = sc.nextint();

if(flag == 1){

now++;

tree rtree = new tree();

head.setrtree(rtree);

rtree.setfronttree(head);//设置父母节点

link_build( head.getrtree() );

}

if( now > save ){

save = now;

}

now--;

}

return head;

}

/*

* 输出树

*/

public tree output(tree head){

int flag;

if(head.getcode() == -1){

return head;

}else{

system.out.println("\n当前位置：" + head.getcode());

system.out.println(head.getltree() != null);

if(head.getltree() != null){

system.out.println("\n访问 左子树:");

output( head.getltree() );

}

if(head.getrtree() != null){

system.out.println("\n访问 右子树:");

output( head.getrtree() );

}

}

return head;

}

/*

* 获得高度

*/

public int getsave(){

return this.save;

}

/*

* 非递归 前序遍历

*/

public void front_traverse(tree head){

tree star = head;//退出标记

int choose = 1; //左

int flag = 1; //右

system.out.println( "" + head.getcode() );//先访问根

while(true){

if( head.getltree() != null && choose != 0 ){

head = head.getltree();

system.out.println( "" + head.getcode() );//获得信息

flag = 1;

}else if( head.getrtree() != null && flag != 0 ){

head = head.getrtree();

system.out.println( "" + head.getcode() );

choose = 1;

}else if( flag == 0 && choose == 0 && head == star){

break;

}else{

if(head == head.getfronttree().getrtree()){

flag = 0;

choose = 0;

}

if(head == head.getfronttree().getltree()){

choose = 0;

flag = 1;

}

head = head.getfronttree();

system.out.println("获得 父母" + head.getcode());

system.out.println( "\n\n\n" );

}

}

}

/*

* 非递归 中序遍历

*/

public void center_traverse(tree head){

tree star = head;//退出标记

int choose = 1; //左

int flag = 1; //右

while(true){

if( head.getltree() != null && choose != 0 ){

head = head.getltree();

flag = 1;

}else if( head.getrtree() != null && flag != 0 ){

if(head.getltree() == null){//因为左边为空而返回

system.out.println( "" + head.getcode());

}

head = head.getrtree();

choose = 1;

}else if( flag == 0 && choose == 0 && head == star){

break;

}else{

int area = 0;//判断哪边回来

flag = 1;

choose = 1;

if(head == head.getfronttree().getrtree()){

area = 1;//右边回来

flag = 0;

choose = 0;

}

if(head == head.getfronttree().getltree()){

area = 2;//左边回来

choose = 0;

flag = 1;

}

if( head.getltree() == null && head.getrtree() == null ){//因为左边为空而返回

system.out.println( "" + head.getcode());

}

head = head.getfronttree();

if( area == 2){//因为左边访问完返回

system.out.println( "" + head.getcode());

}

system.out.println("获得 父母" + head.getcode());

system.out.println( "\n\n\n" );

}

}

}

/*

* 非递归 后续遍历

*/

public void bottom_traverse(tree head){

tree star = head;//退出标记

int choose = 1; //左

int flag = 1; //右

while(true){

if( head.getltree() != null && choose != 0 ){

head = head.getltree();

flag = 1;

}else if( head.getrtree() != null && flag != 0 ){

head = head.getrtree();

choose = 1;

}else if( flag == 0 && choose == 0 && head == star){

break;

}else{

int area = 0;//判断哪边回来

flag = 1;

choose = 1;

if(head == head.getfronttree().getrtree()){

area = 1;//右边回来

flag = 0;

choose = 0;

}

if(head == head.getfronttree().getltree()){

choose = 0;

flag = 1;

}

if(head.getrtree() == null){//因为右边为空而返回

system.out.println( "" + head.getcode());

}

head = head.getfronttree();

if( area == 1){

system.out.println( "" + head.getcode());

}

system.out.println("获得 父母" + head.getcode());

system.out.println( "\n\n\n" );

}

}

}

}

2. tree 类实现：

public class tree {

private int code = -1;

private tree fonttree;

private tree ltree;

private tree rtree;

tree(){

this.code = -1;

this.ltree = null;

this.rtree = null;

}

/*

* 树内容查看方法：

*/

public void setcode(int code){//设置编号

this.code = code;

}

public int getcode(){ //获取编号

return this.code;

}

/*

* 设置父母指针：

*/

public void setfronttree(tree front){

this.fonttree = front;

}

public tree getfronttree(){

system.out.println("获得 父母");

return this.fonttree;

}

/*

* 设置左子女：

*/

public void setltree(tree ltree){

this.ltree = ltree;

}

public tree getltree(){

system.out.println("获得左子树");

return this.ltree;

}

/*

* 设置右子女：

*/

public void setrtree(tree rtree){

this.rtree = rtree;

}

public tree getrtree(){

system.out.println("获得右子树");

return this.rtree;

}

}

3. 主函数测试：

public class mainactivity {

scanner sc = new scanner(system.in);

public static void main(string[] args) {

tree head = new tree();

tree_link link_1st = new tree_link();

head = link_1st.link_build(head);

system.out.println("build succeed !");

system.out.println("\n二叉树高度-->" + link_1st.getsave());

link_1st.output(head);

system.out.println("output over !");

system.out.println("\n\n\n前序访问根：");

link_1st.front_traverse(head);

system.out.println("\n\n\n中序访问根：");

link_1st.center_traverse(head);

system.out.println("\n\n\n后序访问根：");

link_1st.bottom_traverse(head);

system.out.println("\n\n\n\ntext over !\n\n\n");

}

}

希望本文所述对大家java程序设计有所帮助。

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