POJ 2418 Java

开始用基于数组的二叉搜索树来做，由于给的数据建立的树不一定是平衡的，所以很容易发生数组越界，提交了几次都是Runtime Error，因此决定改用基于指针的树结构，结果一次AC了...还是很菜，还要努力。

贴出代码，希望能得到各位大牛指点，也希望能帮助被这题困扰的人，RE还是挺郁闷的......

import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;public class Main {//树节点public static class TreeNode{//树种的名字private String species;private TreeNode left;private TreeNode right;//该树种出现的次数private int count;}public static class Tree{//该区域树的总数private int total;private TreeNode root=new TreeNode();public void insert(String newSpecies,TreeNode root){//树为空if(root.count==0){root.species=newSpecies;root.count++;total++;return;}else{//比该结点小if(root.species.compareTo(newSpecies)>0){if(root.left==null){root.left=new TreeNode();}insert(newSpecies,root.left);}else{if(root.species.compareTo(newSpecies)<0){if(root.right==null){root.right=new TreeNode();}insert(newSpecies,root.right);}else{root.count++;total++;}}}}//树的遍历输出(中序)public void travelTree(TreeNode root){if(root==null){return;}travelTree(root.left);System.out.print(root.species+" ");double p=(double)root.count*100/total;//控制输出精度System.out.printf("%.4f", p);System.out.println();travelTree(root.right);}}public static void main(String[] args){BufferedReader reader=new BufferedReader(new InputStreamReader(System.in));Tree t=new Tree();String s;try {while((s=reader.readLine())!=null){ //本地测试用// if(s.compareTo("0")==0){//// break;//// }// System.out.println(s);t.insert(s,t.root);}} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}//System.out.println("total: "+t.totalCount);t.travelTree(t.root);}}