Programming algorithms-constructing and printing binary trees using Arrays

Create and print binary trees using Arrays

 

Array:

Construct a binary tree, You need to useTwo queues (queue), Save the child and parent nodes, and exchange them;

Print Binary Tree, You need to use two queues to print the Parent and Child Nodes in sequence and exchange them;

 

Binary Tree data structure:

 

struct BinaryTreeNode {int m_nValue;BinaryTreeNode* m_pParent;BinaryTreeNode* m_pLeft;BinaryTreeNode* m_pRight;};

 

 

Code:

 

/* * main.cpp * *  Created on: 2014.6.12 *      Author: Spike *//*eclipse cdt, gcc 4.8.1*/#include 
 
  #include 
  
   #include 
   
    using namespace std;struct BinaryTreeNode {int m_nValue;BinaryTreeNode* m_pParent;BinaryTreeNode* m_pLeft;BinaryTreeNode* m_pRight;};void printTree (BinaryTreeNode* tree){BinaryTreeNode* node = tree;std::queue
    
      temp1;std::queue
     
       temp2;temp1.push(node);while (!temp1.empty()){node = temp1.front();if (node->m_pLeft != NULL) {temp2.push(node->m_pLeft);}if (node->m_pRight != NULL) {temp2.push(node->m_pRight);}temp1.pop();std::cout << node->m_nValue  <<  ;if (temp1.empty()){std::cout << std::endl;temp1 = temp2;std::queue
      
        empty;std::swap(temp2, empty);}}}BinaryTreeNode* buildTree (const std::vector
       
        & L){if (L.empty()) return nullptr;std::queue
        
          parentQueue;std::queue
         
           childQueue;BinaryTreeNode* root = new BinaryTreeNode();root->m_nValue = L[0];parentQueue.push(root);std::size_t times = 1;while (times < L.size()){BinaryTreeNode* parent = parentQueue.front();parentQueue.pop();BinaryTreeNode* lchild = new BinaryTreeNode();lchild->m_nValue = L[times];lchild->m_pLeft = nullptr;lchild->m_pRight = nullptr;++times;parent->m_pLeft = lchild;lchild->m_pParent = parent;childQueue.push(lchild);if (times == L.size()) break;BinaryTreeNode* rchild = new BinaryTreeNode();rchild->m_nValue = L[times];rchild->m_pLeft = nullptr;rchild->m_pRight = nullptr;++times;parent->m_pRight = rchild;rchild->m_pParent = parent;childQueue.push(rchild);if (parentQueue.empty()) {parentQueue = childQueue;std::queue
          
            empty;std::swap(childQueue, empty);}}return root;}int main (void){std::vector
           
             L = {49, 38, 65, 97, 76, 13, 27, 49};BinaryTreeNode* tree = buildTree(L);printTree(tree);return 0;}
           
          
         
        
       
      
     
    
   
  
 

 

Output:

 

49 38 65 97 76 13 27 49