HDOJ 1075 What Are You Talking About（trie树入门）

思路：

字典树：建树，查询。字符串处理稍麻烦点。跑了203MS，还好

 

#include <iostream>

using namespace std;



struct node {

    bool isword;

    int index;

    int child[26];

} trie[1000010] ;



int size = 0;



char dict[1000010][12];

char is[3010], os[3010];



void Insert(char* word, int i, int rt)

{

    if (*word == '\0')

    {

        trie[rt].isword = true;

        trie[rt].index = i;

        return ;

    }



    int m = *word - 'a';

    if (trie[rt].child[m])

    {

        Insert(word + 1, i, trie[rt].child[m]);

    }

    else

    {

        trie[rt].child[m] = ++size;

        Insert(word + 1, i, size);

    }

}



int Query(char* word, int rt)

{

    if (*word == '\0')

    {

        if (trie[rt].isword)

            return trie[rt].index;

        else

            return -1;

    }



    int m = *word - 'a';

    if (!trie[rt].child[m])

        return -1;

    else

        return Query(word + 1, trie[rt].child[m]);

}



int main()

{

    char mars[12];

    int i = 0;



    gets(mars);

    while (scanf("%s%*c", dict[i]))

    {

        if (!strcmp(dict[i], "END"))

            break ;

        scanf("%s%*c", mars);

        Insert(mars, i++, 0);

    }



    gets(mars);

    while (gets(is))

    {

        if (!strcmp(is, "END"))

            break;



        int i = 0, j = 0;

        memset(os, 0, sizeof(os));

        memset(mars, 0, sizeof(mars));



        for (i = 0; is[i] != '\0'; ++i)

        {

            if ('a' <= is[i] && is[i] <= 'z')

                mars[j++] = is[i];

            else

            {

                if (j)

                {

                    int m = Query(mars, 0);

                    if (m == -1)

                        strcat(os, mars);

                    else

                        strcat(os, dict[m]);

                    memset(mars, 0, sizeof(mars));

                    j = 0;

                }

                os[strlen(os)] = is[i];

            }

        }

        printf("%s\n", os);

    }

    return 0;

}