单链表的基本操作，创建插入删除输出。

Posted 2020-10-10 禹某

#ifndef _NODE
#define _NODE
typedef struct Node *PtrNode;
typedef PtrNode List;
typedef PtrNode Position;
typedef int ElementType;
List InitNode();
List Find(int i, List L);
void InSert(ElementType x, int i, List L);
void Delete(int i, List L);
int PrintNode(List L);
List CreateNode();

#endif 
struct Node {
    ElementType Data;
    List Next;
};


#include<stdio.h>
#include<stdlib.h>
#include"Node.h"
List InitNode() {         //初始化头结点
    List L;
    L = (List)malloc(sizeof(struct Node));
    L->Next = NULL; 
    printf("初始化成功\n");
    return L;
}
List Find(int j, List L) {       //查找第几处元素的地址
    int i = 1;
    Position P=L->Next;          //指向第一个元素
    while (P!= NULL&&i < j) {
        P = P->Next;
        i++;
    }
    if (i == j) return P;
    else return NULL;
}
void InSert(ElementType x, int i, List L) {     //在第几处插入数据
    Position P;
    List s;
        if (i == 1) {                           //插在第一个元素时
            s = (List)malloc(sizeof(struct Node));
            s->Data = x;                        //L是头结点
            s->Next = L->Next;          
            L->Next = s;
            return L;
        }
        else {
            P = Find(i - 1, L);        //插在其他地方
            s = (List)malloc(sizeof(struct Node));
            s->Data = x;
            s->Next = P->Next;
            P->Next = s;
            return L;
        }
}
void Delete(int i, List L) {       //删除第几处的元素
    Position s,P;
        if (i == 1) {              //删除第一个元素时
            s = L->Next;
            L->Next = s->Next;
            free(s);
            return L;
        }
        P = Find(i - 1, L);
        if (P->Next == NULL) {
            printf("第%d个结点不存在", i); return NULL;
        }
        else {                   //删除其他处
            s = P->Next;
            P->Next = s->Next;
            free(s);
        }
}
int PrintNode(List L) {            //遍历输出
    L = L->Next;
    while (L) {
        printf("%d\n", L->Data);
        L = L->Next;
    }
}
List CreateNode() {      //创建链表
    int N,x;
    Position P,s,r;
    P = InitNode();
    r = P;          //r指向最后一个元素
    printf("输入要创建几个数据");
    scanf("%d", &N);
    while (N--) {
        printf("输入数据");
        scanf("%d", &x);
        s = (List)malloc(sizeof(struct Node));    //依次向后插入
        s->Data = x;
        s->Next = r->Next;
        r->Next = s;
        r = r->Next;
        r = s;
    }
    return P;
}
int main() {
    int a, b,c;
    List list;
    list=CreateNode();
    printf("输入要插入的数据");
    scanf("%d", &a);
    printf("输入在第几处插入");
    scanf("%d", &b);
    InSert(a, b, list);
    PrintNode(list);
    printf("需要删除第几处的数据");
    scanf("%d", &c);
    Delete(c, list);
    PrintNode(list);
}