UVa 10815 - Andy's First Dictionary

题目：统计单词。

分析：字符串处理、字典树。比较裸的字典树，建树输出即可。

注意：库iostream中没有gets。万恶的CE，╮(╯▽╰)╭。

 

#include <iostream>

#include <cstdlib>

#include <cstring>

#include <cstdio>



using namespace std;



//Trie

typedef struct node1

{

	bool   flag;

	node1 *next[26];

}tnode;

tnode dict[50000];



class Tire

{

		tnode* root;

		int    size;

		char   save[201];

	public:

		Tire() {size = 0;root = newnode();}

		int ID( char ch ) {

			if ( ch <= 'Z' ) return ch-'A';

			else return ch-'a';

		}

		//构造新节点 

		tnode* newnode() {

			for ( int i = 0 ; i < 26 ; ++ i )

				 dict[size].next[i] = NULL;

			dict[size].flag = false;

			return &dict[size ++]; 

		}

		//单词插入 

		void insert( char* word, int len ) {

			tnode *now = root;

			for ( int i = 0 ; i < len ; ++ i ) {

				if ( !now->next[ ID(word[i]) ] )

					now->next[ ID(word[i]) ] = newnode();

				now = now->next[ ID(word[i]) ];

			}now->flag = true;

		}

		//利用dfs遍历输出 

		void output( tnode* r, int d ) {

			if ( r->flag ) {

				save[d] = 0;puts(save);

			}

			for ( int i = 0 ; i < 26 ; ++ i )

				if ( r->next[i] ) {

					save[d] = i+'a';

					output( r->next[i], d+1 );

				}

		}

		void output(){ output(root,0); }

};

//Tire end



int main()

{

	char buf[201],sav[201];

	Tire tire;

	while ( gets(buf) ) {

		int len = strlen(buf);

		int cou = 0;

		for ( int i = 0 ; i <= len ; ++ i )

			if ( (buf[i] >= 'a' && buf[i] <= 'z') ||

				 (buf[i] >= 'A' && buf[i] <= 'Z') )

				sav[cou ++] = buf[i];

			else if ( cou ) {

				sav[cou] = 0;

				tire.insert( sav, cou );

				cou = 0;

			}

	}

	tire.output();

	return 0;

}