先序遍历二叉树

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

//用二叉链表存储方式建树(完全二叉树)
typedef struct BitTree {
	int data;
	struct BitTree* LChild; //左子树
	struct BitTree* RChild; //右子树
}bittree;

//创建二叉树
bittree* createBitTree(bittree* BT) {
	int num = 0;
	scanf("%d", &num);
	if (num != -1) {  //输入-1代表结束
		BT = (bittree*)malloc(sizeof(bittree));
		BT->data = num;
		printf("输入%d的左结点值：", BT->data);
		BT->LChild = createBitTree(BT->LChild);
		printf("输入%d的右结点值：", BT->data);
		BT->RChild = createBitTree(BT->RChild);
	}
	else {
		BT = NULL; //输入-1，结点为NULL
	}
	return BT;
}

//先序遍历
void PrePrint(bittree* BT) {
	if (BT != NULL) { 
		printf("%d ", BT->data);
		PrePrint(BT->LChild);
		PrePrint(BT->RChild);
	}
	else { //结点为NULL，返回上一层
		return;
	}
	
}

void main() {
	bittree* myBT = NULL;
	myBT = createBitTree(myBT);
	printf("先序遍历二叉树：\n");
	PrePrint(myBT);
}