Binary operation (a)

Binary tree traversal

Preorder

It means access to a node in the tree traversal play any of it made after its left subtree, after visiting this node, the number of re-iterate its right child. Which traversal is:
1. preorder its left subtree
2. Access root
3. preorder its right subtree
Code:

void InorderTraversal(BinTree BT)
{
	if(BT)
	{
		InorderTraversal(BT->Left);
		//此处假设对BT结点的访问就是打印数据
		printf("%d",BT->Data);//鸡舍数据为整型
		InorderTraversal(BT->Right); 
	}
}

as the picture shows:

Preorder

It refers to the access node is performed before the left and right sub-tree traversal, the traversal of that:
1. Access root node
2. preorder its left subtree
2. preorder traversal of its right child Number
Code:

void PreorderTraversal(BinTree BT)
{
	if(BT)
	{
		printf("%d",BT->Data);
		PreorderTraversal(BT->Left);
		PreorderTraversal(BT->Right);
	}
}

as the picture shows:

Postorder

It means traversing around first node for a subtree, then this node is the access point that traversal of:
preorder traversal of its left subtree 1. After
2 postorder its right subtree
3. Access root node
Code

void PostorderTraversal(BinTree BT)
{
	if(BT)
	{
		PostorderTraversal(BT->Left);
		PostorderTraversal(BT->Right);
		printf("%d",BT->Data);
	}
}

as the picture shows:

Layer preorder

Characterized traversal sequence from top to bottom, left to right, which is the traversal :( see "binary tree traversal -PTA")

Output binary tree leaf nodes

void PreorderPrintLeaves( BinTree BT )
{
    if(BT){
        if(!BT->Left&&!BT->Right)printf(" %c",BT->Data);
        if(BT->Left)PreorderPrintLeaves(BT->Left);
        if(BT->Right)PreorderPrintLeaves(BT->Right);
        
    }
}

Height binary tree algorithm

Code

int GetHeight( BinTree BT )
{
	int HL,HR,MaxH;
	if(BT)
	{
		HL=GetHeight(BT->Left);
		HR=GetHeight(BT->Right);
		MaxH=HL>HR? HL:HR;
		return (MaxH+1);
	}
	else return 0;
}