【HDOJ】1247 Hat’s Words

字典树。

 #include <cstdio>
 #include <cstring>
 #include <cstdlib>

 #define MAXN 50005
 #define MAXL 25

 typedef struct Trie {
     bool f;
     Trie *next[];
     Trie() {
         f = false;
         for (int i=; i<; ++i)
             next[i] = NULL;
     }
 } Trie;

 Trie root;
 char map[MAXN][MAXL], buf[MAXL];
 int nn = ;

 void create(char str[]) {
     int i = , id;
     Trie *p = &root, *q;

     while (str[i]) {
         id = str[i] - 'a';
         ++i;
         if (p->next[id] == NULL) {
             q = new Trie();
             p->next[id] = q;
         }
         p = p->next[id];
     }
     p->f = true;
 }

 bool find(char str[], int x) {
     int i = , id;
     Trie *p = &root;
     bool f;

     while (i<x && str[i]) {
         id = str[i] - 'a';
         ++i;
         if (p->next[id] == NULL)
             return false;
         p = p->next[id];
     }
     f = p->f;
     if (!f) return false;

     p = &root;
     while (str[i]) {
         id = str[i] - 'a';
         ++i;
         if (p->next[id] == NULL)
             return false;
         p = p->next[id];
     }
     return p->f;
 }

 int main() {
     int i, j, len, n = ;
     bool f;

     while (scanf("%s", map[n]) != EOF)
         create(map[n++]);

     for (i=; i<n; ++i) {
         len = strlen(map[i]);
         f = false;
         for (j=; !f&&j<len-; ++j)
             f = find(map[i], j);
         if (f)
             printf("%s\n", map[i]);
     }

     return ;
 }