2024.1.30

作业1：1.二叉树递归创建  2.二叉树先中后序遍历 3.二叉树计算节点4.二叉树计算深度。

#include
#include
#include
typedef char datatype;
typedef struct Node
{
	//数据域：数据元素
	datatype data;
	//指针域：存储左孩子的节点地址
	struct Node *lchild;
	//指针域：存储右孩子的节点地址
	struct Node *rchild;
}*Btree;
//创建节点
Btree create_node()
{
	Btree s=(Btree)malloc(sizeof(struct Node));
	if(s==NULL)
		return NULL;
	s->data=0;
	s->lchild=s->rchild=NULL;
	return s;
}
//创建二叉树
Btree create_tree()
{
	datatype element;
	printf("please enter element:");
	scanf(" %c",&element);
	if(element=='#')
		return NULL;
	//创建节点
	Btree tree=create_node();
	tree->data=element;
	//递归实现循环创建左孩子
	puts("left");
	tree->lchild=create_tree();
	//递归实现循环创建右孩子
	puts("right");
	tree->rchild=create_tree();
	return tree;
}
void first(Btree tree)
{
	if(tree==NULL)
		return;
	//遍历根
	printf("%c",tree->data);
	//遍历左孩子
	first(tree->lchild);
	//遍历右孩子
	first(tree->rchild);
}
void mid(Btree tree)
{
	if(tree==NULL)
		return;
	//遍历左孩子
	mid(tree->lchild);
	//遍历根
	printf("%c",tree->data);
	//遍历右孩子
	mid(tree->rchild);
}
void last(Btree tree)
{
	if(tree==NULL)
		return;
	//遍历左孩子
	last(tree->lchild);
	//遍历右孩子
	last(tree->rchild);
	//遍历根
	printf("%c",tree->data);

}
void Count(Btree tree,int *n0,int *n1,int *n2)
{
	if(tree==NULL)
		return;
	if(!tree->lchild && !tree->rchild)
		++*n0;
	else if( tree->lchild && tree->rchild )
		++*n2;
	else
		++*n1;
	//递归遍历左孩子
	Count(tree->lchild,n0,n1,n2);
	//递归遍历右孩子
	Count(tree->rchild,n0,n1,n2);
}
int high(Btree tree)
{
	if(tree==NULL)
		return 0;
	//递归计算左子数的深度
	int left=1+high(tree->lchild);
	//递归计算右子树的深度
	int right=1+high(tree->rchild);
	return left>right?left:right;
}
int main(int argc, const char *argv[])
{
	Btree tree=create_tree();
	first(tree);
	puts("");
	mid(tree);
	puts("");
	last(tree);
	puts("");
	int n0=0,n1=0,n2=0;
	Count(tree,&n0,&n1,&n2);
	printf("n0=%d,n1=%d,n2=%d,n=%d",n0,n1,n2,n0+n1+n2);
	int len=high(tree);
	printf("len=%d\n",len);
	return 0;
}

作业2：编程实现快速排序降序 

#include
#include
#include
//一次排序
//返回基准值下标
int one_sort(int arr[],int low,int high)
{
	//确定基准值
	int key=arr[low];
	//当low==high 结束
	//循环low=arr[high])
			high--;
		arr[low]=arr[high];

		//从low开始比较
		while(low=high)
		return;
	//一次排序
	int mid=one_sort(arr,low,high);
	//递归左边子序列
	quick_sort(arr,low,mid-1);
	//递归右边子序列
	quick_sort(arr,mid+1,high);
}
int main(int argc, const char *argv[])
{
	int arr[]={12,3,45,23,345,2,56,34,7};
	int len=sizeof(arr)/sizeof(arr[0]);
	quick_sort(arr,0,len-1);
	for(int i=0;i

作业3：  思维导图