C语言链表

head.h

typedef struct Node_s{int data; //数据域struct Node_s *pNext; //指针域
} Node_t, *pNode_t;void headInsert(pNode_t *ppHead, pNode_t *ppTail, int data);
void print(pNode_t pHead);
void tailInsert(pNode_t *ppHead, pNode_t *ppTail, int data);
void sortInsert(pNode_t *ppHead, pNode_t *ppTail, int data);
void modify(pNode_t pHead, int findNum, int changeNum);
void listDelete(pNode_t *ppHead, pNode_t *ppTail, int deleteNum);

main.c

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "head.h"
int main() {pNode_t pHead = NULL;pNode_t pTail = NULL;int data;while (scanf("%d", &data) != EOF) {//headInsert(&pHead, &pTail, data);//tailInsert(&pHead, &pTail, data);sortInsert(&pHead, &pTail, data);print(pHead);}/*int findNum, changeNum;while (scanf("%d%d", &findNum, &changeNum) != EOF) {modify(pHead, findNum, changeNum);print(pHead);}*/int deleteNum;while (scanf("%d", &deleteNum) != EOF) {listDelete(&pHead, &pTail, deleteNum);print(pHead);}
}
//头插法
void headInsert(pNode_t *ppHead, pNode_t *ppTail, int data) {//在堆上申请空间，存储链表结点pNode_t pNew = (pNode_t)malloc(sizeof(Node_t));memset(pNew, 0, sizeof(Node_t));//数据域为0，指针域为NULLpNew->data = data;if (*ppHead == NULL) {*ppHead = pNew;*ppTail = pNew;}else {pNew->pNext = *ppHead;*ppHead = pNew;}
}
//打印链表
void print(pNode_t pHead) {pNode_t pCur = pHead;while (pCur) {printf("%3d", pCur->data);pCur = pCur->pNext;}printf("\n");
}
//尾插法
void tailInsert(pNode_t *ppHead, pNode_t *ppTail, int data) {pNode_t pNew = (pNode_t)calloc(1, sizeof(Node_t));//使用calloc可以不用执行memset了pNew->data = data;if (*ppHead == NULL) {*ppHead = pNew;*ppTail = pNew;}else {(*ppTail)->pNext = pNew;*ppTail = pNew;}
}
//有序插入
void sortInsert(pNode_t *ppHead, pNode_t *ppTail, int data) {pNode_t pNew = (pNode_t)calloc(1, sizeof(Node_t));pNew->data = data;if (*ppHead == NULL) {//插入唯一的结点*ppHead = pNew;*ppTail = pNew;}else if (data < (*ppHead)->data) {//执行头插法pNew->pNext = *ppHead;*ppHead = pNew;}else {//存在某个结点，其指针域将要改变指向pNode_t pPre = *ppHead;//要修改指针域的结点pNode_t pCur = pPre->pNext;//是pPre的后继，pCur所指结点的数据域决定了是否要插入//经验：写出每次循环迭代的语句，根据这个语句是否有问题，判断循环的条件是否有问题while (pCur) {if (pCur->data > data) {//插入到中间的位置pPre->pNext = pNew;pNew->pNext = pCur;break;}pPre = pCur;pCur = pCur->pNext;}//如果退出循环时，pCur为NULL，说明没有找到中间位置，要执行尾插法if (pCur == NULL) {(*ppTail)->pNext = pNew;*ppTail = pNew;}}
}
//查找和修改
void modify(pNode_t pHead, int findNum, int changeNum) {pNode_t pCur = pHead;while (pCur) {if (pCur->data == findNum) {pCur->data = changeNum;break;}pCur = pCur->pNext;}if (pCur == NULL) {fprintf(stderr, "Cannot find the number!\n");}
}
//删除
void listDelete(pNode_t *ppHead, pNode_t *ppTail, int deleteNum) {pNode_t pCur = *ppHead;//pCur指向待删除的结点，以供后续freeif (pCur == NULL) {fprintf(stderr, "List is empty!\n");return;//return 终止本次函数调用}else if(pCur->data == deleteNum){//删除的是第一个结点*ppHead = (*ppHead)->pNext;//pCur依然指向原来的pHead pHead后移了if (*ppHead == NULL) {//删除之后没有结点，意味着删除的是唯一的结点*ppTail = NULL;}}else {pNode_t pPre = *ppHead;//双指针法，pPre指向要修改指针域的结点pCur = pPre->pNext;while (pCur) {if (pCur->data == deleteNum) {//链表结点删除，意味着其前驱结点的指针域改变了指向pPre->pNext = pCur->pNext;break;}pPre = pCur;pCur = pCur->pNext;}if (pCur == *ppTail) {*ppTail = pPre;}if (pCur == NULL) {fprintf(stderr, "DeleteNum is not found!\n");return;}}free(pCur);pCur = NULL;
}