POJ 2418 Hardwood Species

 这题，我起先用的是AVL树，结果时间超时，最后发现，直接用二叉树就行了，根本就不需要旋转。由于数据是随机的，因而这棵二叉树的性能还行。当然还可以用trie树来解决。

题目很简单，直接上代码

  1 #include <iostream>  2 #include <stack>  3 #include <string.h>  4 #include <stdio.h>  5 #include <stdlib.h>  6 using namespace std;  7   8 class Node  9 { 10 public: 11        char* data; 12        Node* left; 13        Node* right; 14        int balance; 15        int count; 16        Node() 17        { 18                data =http://www.cnblogs.com/shuaiwhu/archive/2012/06/29/ NULL; 19                left = right = NULL; 20                balance = count = 0; 21        } 22        Node(char* s) 23        { 24                data = http://www.cnblogs.com/shuaiwhu/archive/2012/06/29/new char[30]; 25            strcpy(data, s); 26                left = NULL; 27                right = NULL; 28                balance = 0; 29                count = 1; 30        } 31 }; 32  33  34 class AVLTree 35 { 36 private: 37        Node* root; 38  39 public: 40        int vertexNumber; 41        AVLTree() 42        { 43                root = NULL; 44                vertexNumber = 0; 45        } 46  47  48        AVLTree(Node* r) 49        { 50                root = r; 51                vertexNumber = 0; 52        } 53        int depth(Node* node) 54        { 55                if(node == NULL) 56                        return -1; 57                int l = depth(node->left); 58                int r = depth(node->right); 59  60                return (l < r)?(r+1):(l+1); 61        } 62  63        void insert(char* str) 64        { 65                Node* child = root; 66                Node* parent = NULL; 67                Node* grandpa = NULL; 68                int flag; 69  70                if(root == NULL) 71                { 72                        Node* no = new Node(str); 73                        root = no; 74                        return; 75                } 76  77                while(child != NULL) 78                { 79                        if(strcmp(str, child->data) == 0) 80                        { 81                                (child->count)++; 82                                return; 83                        } 84  85                        parent = child; 86                        if(strcmp(str, child->data) < 0) 87                                child = parent->left; 88                        else  89                                child = parent->right; 90                } 91  92                Node* node = new Node(str); 93                if(strcmp(node->data, parent->data) < 0) 94                        parent->left = node; 95                else  96                        parent->right = node;           97        } 98  99        void print(Node* node)100        {101                if(node != NULL)102            {103            print(node->left);104            printf("%s %.4f\n", node->data, (double)(node->count)*100/vertexNumber);105            print(node->right);106            }107        }108 109        Node* getRoot()110        {111                return root;112        }113 };114 115 int main()116 {117        AVLTree* avlTree = new AVLTree();118 119        char str[30];120        while(gets(str) != NULL)121        {122                avlTree->insert(str);123                (avlTree->vertexNumber)++;124        }125        avlTree->print(avlTree->getRoot());       126        return 0;127 }