九度oj 1184 二叉树遍历

原题链接：http://ac.jobdu.com/problem.php?pid=1184

简单的二叉树重建，遍历.

如下：

 

 1 #include<cstdio>

 2 #include<cstdlib>

 3 #include<cstring>

 4 #include<vector>

 5 struct node{

 6     char key;

 7     node *ch[2];

 8     node(char d) : key(d) { ch[0] = ch[1] = NULL; }

 9 }*root = NULL;

10 int n = 0;

11 static int k = -1;

12 char buf[110];

13 void built(node *&p){

14     k++;

15     if (k > n) return;

16     if (buf[k] != '#'){

17         p = new node(buf[k]);

18         built(p->ch[0]);

19         built(p->ch[1]);

20     }

21 }

22 void travle(node *x){

23     if (x != NULL){

24         travle(x->ch[0]);

25         printf("%c ", x->key);

26         travle(x->ch[1]);

27     }

28 }

29 void _free(node *x){

30     if (x != NULL){

31         _free(x->ch[0]);

32         _free(x->ch[1]);

33         delete x;

34     }

35 }

36 int main(){

37 #ifdef LOCAL

38     freopen("in.txt", "r", stdin);

39     freopen("out.txt", "w+", stdout);

40 #endif

41     while (~scanf("%s", buf)){

42         k = -1, root = NULL, n = strlen(buf);

43         built(root);

44         travle(root);

45         _free(root);

46         printf("\n");

47     }

48     return 0;

49 }

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