首页 > ACM题库 > HDU-杭电 > HDU 4287-Intelligent IME-字典树-[解题报告]HOJ
2015
05-23

HDU 4287-Intelligent IME-字典树-[解题报告]HOJ

Intelligent IME

问题描述 :

  We all use cell phone today. And we must be familiar with the intelligent English input method on the cell phone. To be specific, the number buttons may correspond to some English letters respectively, as shown below:
  2 : a, b, c    3 : d, e, f    4 : g, h, i    5 : j, k, l    6 : m, n, o    
  7 : p, q, r, s  8 : t, u, v    9 : w, x, y, z
  When we want to input the word “wing”, we press the button 9, 4, 6, 4, then the input method will choose from an embedded dictionary, all words matching the input number sequence, such as “wing”, “whoi”, “zhog”. Here comes our question, given a dictionary, how many words in it match some input number sequences?

输入:

  First is an integer T, indicating the number of test cases. Then T block follows, each of which is formatted like this:
  Two integer N (1 <= N <= 5000), M (1 <= M <= 5000), indicating the number of input number sequences and the number of words in the dictionary, respectively. Then comes N lines, each line contains a number sequence, consisting of no more than 6 digits. Then comes M lines, each line contains a letter string, consisting of no more than 6 lower letters. It is guaranteed that there are neither duplicated number sequences nor duplicated words.

输出:

  First is an integer T, indicating the number of test cases. Then T block follows, each of which is formatted like this:
  Two integer N (1 <= N <= 5000), M (1 <= M <= 5000), indicating the number of input number sequences and the number of words in the dictionary, respectively. Then comes N lines, each line contains a number sequence, consisting of no more than 6 digits. Then comes M lines, each line contains a letter string, consisting of no more than 6 lower letters. It is guaranteed that there are neither duplicated number sequences nor duplicated words.

样例输入:

1
3 5
46
64448
74
go
in
night
might
gn

样例输出:

3
2
0

题目大意:手机键盘中与数字2相对应的字母有a,b,c;3相对应的字母有d,e,f。给出一些数字串如34,和一些小写字母串。求小写字母对应的数字串出现的次数。字符串abc对应的数字串是111,dh对应的数字串是34。则小写字符串中111出现一次,34出现一次。

程序中也用到简单的hash映射。

#include<stdio.h>
#include<string.h>
int hash[128];
struct TrieNode{
	int no;//对应的数字串的编号,这个编号利于后面对出现次数进行统计
	TrieNode *next[10];
}node[30005];
TrieNode *root = &node[0];
int cnt,result[5005];
char word[10],s[10];
void init()
{
	//每个字母对应的数字
	hash['a']=hash['b']=hash['c']=2;
	hash['d']=hash['e']=hash['f']=3;
	hash['g']=hash['h']=hash['i']=4;
	hash['j']=hash['k']=hash['l']=5;
	hash['m']=hash['n']=hash['o']=6;
	hash['p']=hash['q']=hash['r']=hash['s']=7;
	hash['t']=hash['u']=hash['v']=8;
	hash['w']=hash['x']=hash['y']=hash['z']=9;
}
void initRoot()
{
	int i;
	for(i=0;i<10;i++)
	{
		root->next[i]=NULL;
	}
}
//向字典树中插入新的串。
void insert(char str[],int num)
{
	TrieNode *p = root;
	int len=strlen(str),i,j;
	for(i=0;i<len;i++)
	{
		if(p->next[str[i]-'0']==NULL)
		{
			p->next[str[i]-'0']=&node[cnt];
			for(j=0;j<10;j++)node[cnt].next[j]=NULL;
			node[cnt].no=-1;
			cnt++;
		}
		p=p->next[str[i]-'0'];
	}
	//设置数字串对应的编号
	p->no=num;
}
/** 查询一个字母字符串对应的数字串 */
void query(char str[])
{
	int len=strlen(str),i;
	TrieNode *p=root;
	for(i=0;i<len;i++)
	{
		p=p->next[hash[str[i]]];
		if(p==NULL)break;
	}
	if(p==NULL)return;//该串对应的数字串不存在。
	else{
		if(p->no!=-1)result[p->no]++;
	}
}
int main()
{
	int t,m,n,i;
	scanf("%d",&t);
	init();
	while(t--)
	{
		cnt=1;
		initRoot();
		memset(result,0,sizeof(result));
		scanf("%d%d",&n,&m);
		for(i=0;i<n;i++)
		{
			scanf("%s",word);
			insert(word,i);
		}
		for(i=0;i<m;i++)
		{
			scanf("%s",s);
			query(s);
		}
		for(i=0;i<n;i++)
		{
			//顺序打出每个串出现的次数。
			printf("%d\n",result[i]);
		}
	}
	return 0;
}

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参考:http://blog.csdn.net/mxway/article/details/9205101