hdu 1251(字典树)

 1 /*

 2 *  字典树 

 3 */

 4 #include <cstdio>

 5 #include <cstdlib>

 6 #include <cstring>

 7 #include <iostream>

 8 

 9 using namespace std;

10 

11 const int N = 11;

12 

13 char str[N];

14 struct node {//节点数据 

15     int c;  //统计前缀个数 

16     node *child[26];

17     node() {//初始化 

18         c = 1;

19         for (int i=0; i<26; ++i) child[i] = NULL;

20     }

21 }*root;

22 

23 void insert(char str[]) {

24     node *p = root;

25     for (int k,i=0; str[i]; ++i, p=p->child[k]) {

26         k = str[i] - 'a';

27         if (p->child[k]) ++p->child[k]->c;

28         else p->child[k] = new node();

29     }

30 }

31 

32 int search(char str[]) {

33     node *p = root;

34     for (int k,i=0; str[i]; ++i) {

35         k = str[i] - 'a';

36         if (p->child[k]) p = p->child[k];

37         else return 0;

38     }

39     return p->c;

40 }

41 

42 int main() {

43     root = new node();

44     while (gets(str), strcmp(str, "")) insert(str);

45     while (scanf("%s", str) != EOF) printf ("%d\n", search(str));

46     return 0;

47 }