小經驗：在VS2017中，使用while（scanf（“%d”,&i）!= NULL）{......}時，結束輸入需要輸入三次ctrl+z+空格

func.h

#include <stdlib.h>
#include <string.h>

typedef struct student {
    int number;
    struct student* pnext;
}stu, *pstu; 

void list_print(pstu);//打印
void list_head_insert(pstu*,pstu*,int
 
);//頭插法
void list_tail_insert(pstu*, pstu*, int);//尾插法
void list_sort_insert(pstu*, pstu*, int);//有序插入
void list_delete(pstu*, pstu*, int);//節點刪除

func.c

#include "func.h"

void list_head_insert(pstu* pphead, pstu* pptail, int i) 
{//頭插法
    pstu pnew;
    pnew = (pstu)malloc(sizeof(stu));//申請空間
    memset(pnew,0
 
,sizeof(stu));//初始化

    pnew->number = i;

    if (*pphead == NULL) {//鏈表為空，新節點既是頭指針，又是尾指針
        *pphead = pnew;
        *pptail = pnew;
    }
    else {
        pnew->pnext = *pphead;//原有的鏈表頭作為新節點的pnext
        *pphead = pnew;//新節點作為節點頭
    }
}

void list_tail_insert(pstu* pphead, pstu* pptail, int
 
 i)
{//尾插法實現
    pstu pnew;
    pnew = (pstu)calloc(1, sizeof(stu));//calloc會進行空間初始化
    pnew->number = i;
    if (*pptail == NULL) {
        *pphead = pnew;
        *pptail = pnew;
    }
    else
    {
        (*pptail)->pnext = pnew;//新節點變成原有尾節點的pnext
        *pptail = pnew;//新節點變成尾節點
    }
}

void list_sort_insert(pstu* pphead, pstu* pptail, int i)
{//有序插入實現
    pstu pcur,ppre;//遊標
    pcur = *pphead;
    ppre = *pphead;

    pstu pnew;
    pnew = (pstu)calloc(1, sizeof(stu));//calloc會進行空間初始化
    pnew->number = i;

    if (*pptail == NULL) {//鏈表為空
        *pphead = pnew;
        *pptail = pnew;
    }
    else if (i<(*pphead)->number)//小於頭結點，類似頭插法
    {
        pnew->pnext = *pphead;//原有的鏈表頭作為新節點的pnext
        *pphead = pnew;//新節點作為節點頭
    }else
    {
        while (pcur!=NULL)
        {//插入中間
            if (i<pcur->number) 
            {
                ppre->pnext = pnew;
                pnew->pnext = pcur;
                break;
            }
            ppre = pcur;
            pcur = pcur->pnext;
        }
        if (pcur == NULL) 
        {//pcur為null，說明插入尾節點
            (*pptail)->pnext = pnew;
            *pptail = pnew;
        }
    }
}

void list_delete(pstu* pphead, pstu* pptail, int d) 
{//刪除實現
    pstu ppre = *pphead, pcur = *pphead;
    if (*pphead == NULL) //鏈表為空
    {
        printf("List is empty\n");
        return;
    }else if(pcur->number==d)//頭結點刪除
    {
        *pphead = pcur->pnext;
        if (*pphead == NULL) {//刪除節點後，鏈表為空
            *pptail = NULL;
        }
        free(pcur);
    }else//刪除中間和尾部
    {
        while (pcur != NULL) 
        {
            if (pcur->number == d) 
            {
                ppre->pnext = pcur->pnext;
                break;
            }
            ppre = pcur;
            pcur = pcur->pnext;
        }
        if (pcur==*pptail) //刪除的是尾節點
        {
            *pptail = ppre;
        }
        if (pcur == NULL) //未找到節點
        {
            printf("This node is not in list\n");
        }
        else
        {
            free(pcur);
        }
    }
}

void list_print(pstu phead) {
    while (phead != NULL)
    {
        printf("%3d", phead->number);
        phead = phead->pnext;
    }    
    printf("\n");
}

main.c

#include "func.h"

int main() {
    pstu phead = NULL;
    pstu ptail = NULL;
    int i;
     while(scanf("%d",&i)!=EOF)
    {
        //list_head_insert(&phead, &ptail,i);//頭插法
        //list_tail_insert(&phead, &ptail, i);//尾插法
        list_sort_insert(&phead, &ptail, i);//有序插入
    }
    list_print(phead);
    while (scanf("%d", &i) != EOF) {
        list_delete(&phead, &ptail, i);
        list_print(phead);
    }
    system("pause");    
}

C語言鏈表的增刪查改