HDU 1075 What Are You Talking About （Trie）

What Are You Talking About

Time Limit: 10000/5000 MS (Java/Others)    Memory Limit: 102400/204800 K (Java/Others)

Total Submission(s): 16042    Accepted Submission(s): 5198

Problem Description

Ignatius is so lucky that he met a Martian yesterday. But he didn't know the language the Martians use. The Martian gives him a history book of Mars and a dictionary when it leaves. Now Ignatius want to translate the history book
into English. Can you help him?

 

Input

The problem has only one test case, the test case consists of two parts, the dictionary part and the book part. The dictionary part starts with a single line contains a string "START", this string should be ignored, then some lines
follow, each line contains two strings, the first one is a word in English, the second one is the corresponding word in Martian's language. A line with a single string "END" indicates the end of the directory part, and this string should be ignored. The book
part starts with a single line contains a string "START", this string should be ignored, then an article written in Martian's language. You should translate the article into English with the dictionary. If you find the word in the dictionary you should translate
it and write the new word into your translation, if you can't find the word in the dictionary you do not have to translate it, and just copy the old word to your translation. Space(' '), tab('\t'), enter('\n') and all the punctuation should not be translated.
A line with a single string "END" indicates the end of the book part, and that's also the end of the input. All the words are in the lowercase, and each word will contain at most 10 characters, and each line will contain at most 3000 characters.

 

Output

In this problem, you have to output the translation of the history book.

 

Sample Input

START
from fiwo
hello difh
mars riwosf
earth fnnvk
like fiiwj
END
START
difh, i'm fiwo riwosf.
i fiiwj fnnvk!
END

 

Sample Output

hello, i'm from mars.
i like earth!

解析：将词典中的原始单词组织成Trie，相应的相应单词作为原始单词的附加信息放到Trie树中原始单词的最后一个字符结点中。

AC代码：

//#include <bits/stdc++.h>       //hdu的C++，不支持此头文件。G++支持
#include <cstdio>
#include <cstring>
#include <cctype>

using namespace std;

const int maxw = 12;
const int maxnode = 100000 * maxw + 10;
const int sigma_size = 26;

struct Trie{
    int ch[maxnode][sigma_size];
    char val[maxnode][maxw];
    int sz;

    void clear(){ sz = 1; memset(ch[0], 0, sizeof(ch[0])); }
    int idx(char c){ return c - 'a'; }

    void insert(const char *s, const char *v){
        int u = 0, n = strlen(s);
        for(int i=0; i<n; i++){
            int c = idx(s[i]);
            if(!ch[u][c]){
                memset(ch[sz], 0, sizeof(ch[sz]));
                ch[u][c] = sz++;
            }
            u = ch[u][c];
        }
        strcpy(val[u], v);
    }

    char* find(const char *s){
        int u = 0, n = strlen(s);
        int i;
        char ans[maxw];
        for(i=0; i<n; i++){
            int c = idx(s[i]);
            if(!ch[u][c]) return "";
            u = ch[u][c];
        }
        return val[u];
    }
};

Trie trie;

int main(){
    #ifdef sxk
        freopen("in.txt", "r", stdin);
    #endif // sxk

    trie.clear();
    char s[maxw], ss[maxw], text[3002];
    scanf("%s", s);
    while(scanf("%s", s)){
        if(s[0] == 'E' && s[1] == 'N' && s[2] == 'D') break;
        scanf("%s", ss);
        trie.insert(ss, s);
    }
    scanf("%s", s);
    getchar();
    while(gets(text)){
        if(text[0] == 'E' && text[1] == 'N' && text[2] == 'D') break;
        int n = strlen(text);
        for(int i=0; i<n; ){
            char foo[maxw];
            int cnt = 0;
            while(i < n && isalpha(text[i])){ foo[cnt ++] = text[i ++]; }
            foo[cnt] = '\0';
            if(!cnt){ putchar(text[i ++]); continue; }
            if(strcmp(trie.find(foo), "")) printf("%s", trie.find(foo));
            else printf("%s", foo);
        }
        puts("");
    }
    return 0;
}