1 #include 
     
       2 #include 
      
        3 struct BSTNode{ 4 int v; 5 struct BSTNode *left,*right; 6 }; 7  8 struct BSTNode *root=NULL; 9 10 struct BSTNode* createNode(int data){11 struct BSTNode *newNode;12 newNode=(struct BSTNode*)malloc(sizeof(struct BSTNode));13 newNode->v=data;14 newNode->left=NULL;15 newNode->right=NULL;16 return newNode;17 }18 19 void insertion(struct BSTNode **node,int data){20 if(*node==NULL){21 *node=createNode(data);22 }else if(data<(*node)->v){23 insertion(&(*node)->left,data);24 }else if(data>(*node)->v){25 insertion(&(*node)->right,data);26 }27 }28 void traverse(struct BSTNode *node){29 if(node!=NULL){30 traverse(node->left);31 std::cout<
       
        v;32 traverse(node->right);33 }34 return;35 }36 int main(){37 int data,ch;38 insertion(&root,10);39 insertion(&root,16);40 insertion(&root,8);41 insertion(&root,20);42 insertion(&root,21);43 traverse(root);44 std::cin>>data;45 }