【POJ】2418 Hardwood Species

简单字典树。

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

 #define MAXN 128

 typedef struct Trie {
     int count;
     Trie *next[MAXN];
     Trie() {
         count = ;
         for (int i=; i<MAXN; ++i)
             next[i] = NULL;
     }
 } Trie;

 Trie root;
 char buf[];
 double n = ;

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

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

 void dfs(Trie *t, int d) {
     int i;

     if (t->count) {
         buf[d] = '\0';
         printf("%s %.4lf\n", buf, t->count*100.0/n);
     }
     for (i=; i<MAXN; ++i) {
         if (t->next[i]) {
             buf[d] = i;
             dfs(t->next[i], d+);
         }
     }
 }

 int main() {
     while (gets(buf) != NULL) {
         create(buf);
         n += 1.0;
     }
     dfs(&root, );
     return ;
 }