中序后序建二叉树

Posted 2022-05-02 masteryan576356467

 1 class tree
 2 private:
 3     struct TNode
 4         int date;
 5         TNode *lchild, *rchild;
 6     ;
 7 
 8 
 9     /*vector<int> post;
10     vector<int> in;*/
11 
12     int post[50];
13     int in[50];
14 
15 public:
16 
17 
18     tree()
19 
20 
21         int N;
22         cin >> N;
23         for(int i = 0; i < N; i++)
24             cin >> in[i];
25         
26         for(int i = 0; i < N; i++)
27             cin >> post[i];
28         
29 
30         TNode *T = createTree(0, N - 1, 0, N - 1);
31 
32         Print(T);
33 
34     
35 
36     TNode * createTree(int postL, int postR, int inL, int inR)
37 
38         if(postL > postR)
39             return NULL;
40         
41         TNode *root = new TNode;
42         root->date = post[postR];
43         int k;
44         for(k = inL; k <= inR; k++)
45             if(in[k] == post[postR])
46                 break;
47         
48         int numLeft = k - inL;
49         root->lchild = createTree(postL, postL + numLeft - 1, inL, k - 1);
50         root->rchild = createTree(postL + numLeft, postR - 1, k + 1, inR);
51         return root;
52     
53 
54 
55     
56 
57     ~tree() 
58 ;