纯c语言实现链表，实现链表增删改查

来源：互联网发布：卷积矩阵及其运算实例编辑：程序博客网时间：2024/06/05 06:41
#include <stdio.h>#include <string.h>#include <stdlib.h>struct selflist{   int num;   selflist* next;};struct selflist* head = NULL;//根据大小创建链表void init(int size){    struct selflist* tmp = NULL;struct selflist* tail = NULL;head = (struct selflist*) malloc(sizeof(struct selflist));if(NULL==head){  printf("初始化链表头失败\n");  return;}head->next = NULL;tmp = head;for(int i = 0; i < size-1; i++){tmp->num = i;//rand();tmp->next = NULL;tail = tmp;tmp = tmp->next;tmp = (struct selflist*) malloc(sizeof(struct selflist));if(NULL==tmp){        printf("初始化临时链表失败\n");        return;}tail->next = tmp;}  ///最后一个无须在malloc空间tail->next->num = size-1;tail->next->next = NULL;}//释放链表的每个节点void FreeList(){    if(NULL==head) return;struct selflist* tmp = head->next;while(head){    free(head);head=NULL;if(tmp){head = tmp;tmp = tmp->next;}}}//末尾插入元素void insert(int num){   struct selflist* tmp = head;   while(tmp){   if(NULL == tmp->next){     struct selflist*  insert = (struct selflist*) malloc(sizeof(struct selflist));             if(insert){ insert->num = num; insert->next = NULL;             tmp->next = insert;             }else{               printf("加入数据失败\n");             } return;   }   tmp = tmp->next;   }  }//指定位置加入数据void insert_ex(int num, int pos){   //pos从0开始，如pos=0,则表示在head前加入一个元素int size=0;struct selflist* tmp = head;//临时复制head，对tmp操作只是不会影响head仍然指向头while(tmp){   ++size;   tmp = tmp->next;}if(pos<0 || pos>=size) {//加入链表末尾  insert(num);}else{   size = 0;   struct selflist*  insert = (struct selflist*) malloc(sizeof(struct selflist));   if(!insert){   printf("指定位置加入元素失败\n");   return;   }   insert->num = num;   insert->next = head;   if(pos==size){   head = insert;   return;   }   tmp = head;   struct selflist* p = NULL;   while(tmp){   if(pos-1==size){   p = tmp->next;   tmp->next = insert;   insert->next = p;   return;   }   tmp = tmp->next;   ++size;   }}}//删除指定位置元素void deletelist(int pos){if(NULL==head) return;if(pos==0){  struct selflist* p = head;  struct selflist* t = head->next;      free(p);  p=NULL;  head = t;  return;}int size=0;struct selflist* tmp = head;while(tmp){   ++size;   tmp = tmp->next;}if(pos<0 || pos>=size){//删除末尾      pos = size-1;}tmp = head;size = 0;while(tmp){if(pos-1==size){struct selflist* p = tmp->next->next;free(tmp->next);tmp->next = NULL;tmp->next  = p;return;}tmp = tmp->next;++size;}}//删除指定元素void deletenum(int num, bool flag){  //flag:true//删除所有为num的元素  //flag:false//只删除找到第一个num的元素  if(NULL==head) return;  struct selflist* tmp = head;  int size=0;  while(tmp){  ++size;  if(tmp->num == num){      deletelist(size-1);  tmp = tmp->next;  if(flag) continue;  else break;  }  tmp = tmp->next;  }}/*  位置从0开始  flag:true://找所有num  flag:false;//找第一个num*/void findnum(int num, bool flag){    if(NULL==head) return;struct selflist* tmp = head;int size = 0;while(tmp){if(tmp->num == num){  printf("找到%d元素，位于链表第%d位置\n",num,size);  tmp = tmp->next;  if(flag) continue;  else break;}tmp = tmp->next;++size;}}//打印链表void Print(){struct selflist* tmp = head;while(tmp){   printf("%d\n",tmp->num);        tmp = tmp->next;}}//链表倒序void reverse(){    if(NULL==head) return;struct selflist* s = NULL;struct selflist* t = head->next;//保存当前链表地址,head的改变不会影响此时的t，但t的改变会影响headwhile(head){head->next = s;//指向前一个节点s = head;//前一个节点，这个head为前面的head->next的head即新的链表head = t;//下一个节点,这个head为原来的head只是变为head->next即原来的链表if(NULL==t) break;//说明是最后一个节点了。if(head){  t = head->next;//得到下一个节点}    }head = s;}
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