output leaf node in preorder

This question requires outputting the leaf nodes of a given binary tree in the order of preorder traversal.

Function interface definition:

void PreorderPrintLeaves( BinTree BT );

where BinTreethe structure is defined as follows:

typedef struct TNode *Position;
typedef Position BinTree;
struct TNode{
    
    
    ElementType Data;
    BinTree Left;
    BinTree Right;
};

The function PreorderPrintLeavesshould output the leaf nodes of the given binary tree in the order of preorder traversal BT, formatted as a space followed by a character.

Sample referee test procedure:

#include <stdio.h>
#include <stdlib.h>

typedef char ElementType;
typedef struct TNode *Position;
typedef Position BinTree;
struct TNode{
    
    
    ElementType Data;
    BinTree Left;
    BinTree Right;
};

BinTree CreatBinTree(); /* 实现细节忽略 */
void PreorderPrintLeaves( BinTree BT );

int main()
{
    
    
    BinTree BT = CreatBinTree();
    printf("Leaf nodes are:");
    PreorderPrintLeaves(BT);
    printf("\n");

    return 0;
}
/* 你的代码将被嵌在这里 */

Sample output (for the tree given in the figure):

Leaf nodes are: D E H I

代码长度限制16 KB
时间限制400 ms
内存限制64 MB

Answer:

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

test: