POJ 2418 Hardwood Species(trie 树）

题目链接

开始想用map的，字典序不会搞，还是老老实实的用trie树把。好久没写了，忘得差不多了。

 1 #include <iostream>

 2 #include <cstdio>

 3 #include <cstdlib>

 4 #include <cstring>

 5 #include <map>

 6 #include <cmath>

 7 #include <string>

 8 #include <queue>

 9 #include <vector>

10 #include <algorithm>

11 using namespace std;

12 struct node

13 {

14     int data;

15     struct node *next[129];

16 };

17 int num = 0;

18 char o[51];

19 struct node *build()

20 {

21     int i;

22     node *p;

23     p = new node;

24     p -> data = 0;

25     for(i = 0; i <= 128; i ++)

26         p -> next[i] = NULL;

27     return p;

28 }

29 void insert(struct node *head,char *str)

30 {

31     int i,len;

32     len = strlen(str);

33     node *p;

34     p = head;

35     for(i = 0; i < len; i ++)

36     {

37         if(p->next[str[i]] == NULL)

38         {

39             p->next[str[i]] = build();

40         }

41         p = p->next[str[i]];

42     }

43     p -> data ++;

44 }

45 void dfs(struct node *head,int step)

46 {

47     int i;

48     node *p;

49     p = head;

50     if(p->data > 0)

51     {

52         o[step] = '\0';

53         printf("%s %.4lf\n",o,p->data*100.0/num);

54     }

55     for(i = 0; i <= 128; i ++)

56     {

57         if(p->next[i] != NULL)

58         {

59             o[step] = i;

60             dfs(p->next[i],step+1);

61         }

62     }

63 }

64 int main()

65 {

66     char p[51];

67     node *head;

68     head = build();

69     while(gets(p) != 0)

70     {

71         insert(head,p);

72         num ++;

73     }

74     dfs(head,0);

75     return 0;

76 }