單鏈表的使用

#include<stdio.h>
#include<malloc.h>
typedef int DataType;  //定義線性表的數據類型 假設爲int型
typedef struct Node   //定義單鏈表的節點類型

{

	DataType data;
	struct Node *next;
} Node;
Node *CreatList(DataType a[],int n)
{
	Node *s = NULL;
	Node *first  = (Node *)malloc(sizeof(Node));
	first->next = NULL;    //初始化節點
	for (int i = 0; i < n; i++)
	{
		s = (Node *)malloc(sizeof(Node));
		s -> data = a[i];   //爲每個數組元素建立一個節點
		s -> next = first -> next; first ->next = s; //將節點s插入到頭結點 之後

	}
	return first;
}
void PrintList(Node *first)
{
	Node *p = first -> next;  //工作指針p初始化
	while (p != NULL)
	{
		printf("%d", p -> data); //輸出節點的數據域 假設爲int型
		p = p -> next;         //工作指針p後移，注意不能寫作p++
	}
	printf("\n");
}
int Length(Node *first)
{
	Node *p = first -> next; //工作指針p初始化
	int count  =  0;  //累加器count初始化
    while (p != NULL)
	{
		p = p -> next;
		count++;
	}
	return count;
}

int Insert (Node *first,int i, DataType x)
{
	Node *s = NULL, *p = first;  //工作指針後移
    int count = 0;
	while ( p != NULL && count < i -1)
	{
		p = p -> next;
		count ++;
	}
	if(p == NULL)  { printf("位置錯誤，插入失敗\n");  return 0; }
    else {
		s = (Node   *)malloc(sizeof(Node));
		s ->  data = x;
		s ->  next = p ->next = s;
		return 1;
	}
}
int main()
{
	int r[5] = {1, 2, 3, 4, 5}, i, x;
	Node *first = NULL;
	first = CreatList(r, 5);
	printf("當前線性表的數據爲:");
	PrintList(first);  //輸出當前鏈表 1 2 3 4 5
	Insert(first, 2, 8);   //在第二個位置插入值爲8的節點
	printf("執行插入操作後數據爲:");
	PrintList(first);     //輸出輸入後鏈表1 8 2 3 4 5
	printf("當前單鏈表的長度爲：%d\n", Length(first));
    getchar();  getchar();
	return 0;
}