【POJ】1056 IMMEDIATE DECODABILITY

字典树水题。

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

 typedef struct Trie {
     bool v;
     Trie *next[];
 } Trie;

 Trie *root;

 bool create(char str[]) {
     int i = , id;
     bool ret = false;
     Trie *p = root, *q;

     while (str[i]) {
         id = str[i] - '';
         ++i;
         if (p->next[id] == NULL) {
             q = (Trie *)malloc(sizeof(Trie));
             q->v = false;
             q->next[] = q->next[] = NULL;
             p->next[id] = q;
             ret = true;
         } else {
             if (p->next[id]->v)
                 return false;
         }
         p = p->next[id];
     }
     p->v = true;

     return ret;
 }

 void del(Trie *t) {
     if (t == NULL)
         return ;
     del(t->next[]);
     del(t->next[]);
     free(t);
 }

 int main() {
     int t = ;
     char buf[];
     bool f = true;
     root = (Trie *)malloc(sizeof(Trie));
     root->next[] = root->next[] = NULL;
     while (scanf("%s", buf) != EOF) {
         if (buf[] == '') {
             ++t;
             if (f)
                 printf("Set %d is immediately decodable\n", t);
             else
                 printf("Set %d is not immediately decodable\n", t);
             f = true;
             del(root);
             root = (Trie *)malloc(sizeof(Trie));
             root->next[] = root->next[] = NULL;
         } else {
             if (f)
                 f = create(buf);
         }
     }

     return ;
 }