由先序遍历序列和中序遍历序列恢复二叉树以及统计叶子节点个数和树的深度

 1 #include <fstream>

 2 #include <iostream>

 3 

 4 using namespace std;

 5 

 6 struct node

 7 {

 8     char c;

 9     struct node *lch,*rch;

10 };

11 

12 int count_leaf(node* tree);//统计叶子结点

13 int count_deep(node* tree);//统计树的深度

14 void create_tree(char* l,char* r,int i,int j,int e,int f,node** tree);//由先序遍历序列和中序遍历序列恢复二叉树

15 

16 int main()

17 {

18     //freopen("D:\\input.in","r",stdin);

19     //freopen("D:\\output.out","w",stdout);

20     node *tree;
21     char pre[]="ABDGCEF";

22     char in[]="DGBAECF";

23     create_tree(pre,in,0,6,0,6,&tree);

24     cout<<count_leaf(tree)<<endl;

25     cout<<count_deep(tree)<<endl;

26     return 0;

27 }

28 int count_leaf(node* tree)

29 {

30     if(tree==NULL)  return 0;

31     if(tree->lch==NULL&&tree->rch==NULL)    return 1;

32     return count_leaf(tree->lch)+count_leaf(tree->rch);

33 }

34 int count_deep(node* tree)

35 {

36     if(tree==NULL)  return 0;

37     return 1+max(count_deep(tree->lch),count_deep(tree->rch));

38 }

39 void create_tree(char* l,char* r,int i,int j,int e,int f,node** tree)

40 {

41     int m;

42     (*tree)=new node;

43     (*tree)->c=l[i];

44     m=e;

45     while(r[m]!=l[i])    m++;

46     if(m==e)    (*tree)->lch=NULL;

47     else    create_tree(l,r,i+1,i+m-e,e,m-1,&(*tree)->lch);

48     if(m==f)    (*tree)->rch=NULL;

49     else    create_tree(l,r,i+m-e+1,j,m+1,f,&(*tree)->rch);

50 }