简单字典树。

1 #include 
     
       2 #include 
      
        3 #include 
       
         4  5 #define MAXN 128 6  7 typedef struct Trie { 8     int count; 9     Trie *next[MAXN];10     Trie() {11         count = 0;12         for (int i=0; i
        
         next[id] == NULL) {29             q = new Trie();30             p->next[id] = q;31         }32         p = p->next[id];33     }34     p->count++;35 }36 37 void dfs(Trie *t, int d) {38     int i;39 40     if (t->count) {41         buf[d] = '\0';42         printf("%s %.4lf\n", buf, t->count*100.0/n);43     }44     for (i=0; i
         
          next[i]) {46             buf[d] = i;47             dfs(t->next[i], d+1);48         }49     }50 }51 52 int main() {53     while (gets(buf) != NULL) {54         create(buf);55         n += 1.0;56     }57     dfs(&root, 0);58     return 0;59 }