Rebuilding a binary tree from a central sequence of a binary tree

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• Lab questions (6 questions in total, 4th questions)

 Lab questions (6 questions in total, 4th questions)

 
 

  
  
 
   
 
    
Title:
 
    
Rebuilding a binary tree from a central sequence of a binary tree
 
   
 
   
 
    
Time limit:
 
    
1000 MS
 
   
 
   
 
    
Memory limit:
 
    
10000 K
 
   
 
   
 
    
Total time limit:
 
    
3000 MS
 
   
 
   
 
    
Description:
 
    
Given the central sequence and sequence output of a binary tree, generate the tree and output the node information in the tree structure in the first and last order as an integer.
 
   
 
   
 
    
Input:
 
    
 
     
 
      
 
       
 
        
Number of Tree nodes sequence output sequence medium sequence input sequence
 
       
 
      
 
     
 
   
 
   
 
    
Output:
 
    
First, then
 
   
 
   
 
    
Input example:
 
    
 
     
 
      
 
       
 
        
6
 
       
 
      
 
     
1 2 3 5 6 72 5 1 6 3 7
 
   
 
   
 
    
Output example:
 
    
1 2 5 3 6 75 2 6 7 3 1
 
   
 
   
 
    
Tip:
 
    
The output 1st of the sequence are root nodes.
 
   
 
   
 
    
Source:
 
   
 
  
 
 

# Include <stdio. h> # include <stdlib. h> int * level; int * In; typedef struct bitnode {int data; bitnode * lchild; bitnode * rchild; // left and right child pointer} bitnode, * bitree; typedef struct qelemnode {int data; int L, H; // lower bound and Upper Bound bitree parent of the central sequence; // int LR; // LR = 1-> left subtree of the parent; LR = 2-> right subtree of the parent; LR = 0-> root node} qelemnode; typedef qelemnode qelemtype; typedef struct qnode {qelemtype data; struct qnode * Next;} qnode, * queueptr; typed EF struct {queueptr front; queueptr rear;} linkqueue; bitree t; void initqueue (linkqueue & Q) {q. front = Q. rear = (queueptr) malloc (sizeof (qnode); If (! Q. front) Exit (0); q. front-> next = NULL;} void enqueue (linkqueue & Q, qelemtype e) {queueptr P; P = (queueptr) malloc (sizeof (qnode); If (! P) Exit (0); P-> DATA = E; P-> next = NULL; q. rear-> next = P; q. rear = P;} void dequeue (linkqueue & Q, qelemtype & E) {queueptr P; If (Q. front = Q. rear) Exit (0); P = Q. front-> next; E = p-> data; q. front-> next = p-> next; If (Q. rear = P) Q. rear = Q. front; free (p);} int queueempty (linkqueue q) {If (Q. front = Q. rear) return 1; else return 0;} void initbitree (bitree & T) {T = NULL;} void destroybitree (bitree & T) {If (t) // non-empty tree {If (t-> lchi LD) // destroybitree (t-> lchild) with the left child; // destroy the left child subtree if (t-> rchild) // destroybitree (t-> rchild) with the right child; // destroy the right child subtree free (t); // release the root node T = NULL; // NULL pointer assigned 0} void postordertraverse (bitree t) {If (T! = NULL) {postordertraverse (t-> lchild); postordertraverse (t-> rchild); printf ("% d", T-> data );}} void preordertraverse (bitree t) {If (T! = NULL) {printf ("% d", T-> data); preordertraverse (t-> lchild); preordertraverse (t-> rchild );}} bitree createbitreefromlevelinorder (int * level, int * In, int N) {int r =-1, low, high, LR, I, j; bitree root = NULL, P, F; int ch; qelemtype s; linkqueue Q; initqueue (Q); S. data = level [++ R]; S. L = 0; S. H = n-1; S. parent = NULL; S. LR = 0; enqueue (Q, S); While (! Queueempty (q) {dequeue (Q, S); CH = S. data; Low = S. l; high = S. h; F = S. parent; LR = S. LR; For (j = low; j <= high; j ++) if (in [J] = CH) {I = J; break;} p = (bitree) malloc (sizeof (bitnode); P-> DATA = CH; P-> lchild = p-> rchild = NULL; If (LR = 0) root = P; else if (LR = 1) F-> lchild = P; else f-> rchild = P; If (Low = high) continue; if (I = low) // No left child at the node {S. L = low + 1; S. LR = 2; S. data = level [++ R]; S. parent = P; enqueue (Q, S);} else if (I = high) // The node has no right child {S. H = high-1; S. LR = 1; S. data = level [++ R]; S. parent = P; enqueue (Q, S);} else // The node has left and right children {S. H = I-1; S. L = low; S. LR = 1; S. data = level [++ R]; S. parent = P; enqueue (Q, S); S. L = I + 1; S. H = high; S. LR = 2; S. data = level [++ R]; S. parent = P; enqueue (Q, S) ;}} return root;} int main () {initbitree (t); int N; int I; scanf ("% d ", & N); Level = (int *) malloc (sizeof (INT) * n); In = (int *) malloc (sizeof (INT) * n ); for (I = 0; I <n; I ++) {scanf ("% d", level + I) ;}for (I = 0; I <N; I ++) {scanf ("% d", in + I);} t = createbitreefromlevelinorder (level, in, n); preordertraverse (t ); printf ("\ n"); postordertraverse (t); Return 0 ;}