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
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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( "<---前序遍历--->" + head.getcode() );//先访问根 while(true){ if( head.getltree() != null && choose != 0 ){ head = head.getltree(); system.out.println( "<---前序遍历--->" + head.getcode() );//获得信息 flag = 1; }else if( head.getrtree() != null && flag != 0 ){ head = head.getrtree(); system.out.println( "<---前序遍历--->" + 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( "<-1--中序遍历--->" + 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( "<-2--中序遍历--->" + head.getcode()); } head = head.getfronttree(); if( area == 2){//因为左边访问完返回 system.out.println( "<-3--中序遍历--->" + 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( "<-1--后序遍历--->" + head.getcode()); } head = head.getfronttree(); if( area == 1){ system.out.println( "<-2--后序遍历--->" + head.getcode()); } system.out.println("获得 父母" + head.getcode()); system.out.println( "\n\n\n" ); } } }} |
2. tree 类实现：
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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：
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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<----------------前------------------>\n前序访问根："); link_1st.front_traverse(head); system.out.println("\n\n<----------------中------------------>\n中序访问根："); link_1st.center_traverse(head); system.out.println("\n\n<----------------后------------------>\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。
原文链接：https://blog.csdn.net/qq_43377749/article/details/83475907
