C語(yǔ)言單鏈表實(shí)現(xiàn)方法詳解

#ifndef __SLIST_H__
#define __SLIST_H__
#include<cstdio>
#include<malloc.h>
#include<assert.h>
typedef int ElemType;
typedef struct Node { //定義單鏈表中的結(jié)點(diǎn)信息
  ElemType data; //結(jié)點(diǎn)的數(shù)據(jù)域
  struct Node *next; //結(jié)點(diǎn)的指針域
}Node,*PNode;
typedef struct List { //定義單鏈表的鏈表信息
  PNode first; //first指向單鏈表中的第一個(gè)結(jié)點(diǎn)
  PNode last; //last指向單鏈表中的最后一個(gè)結(jié)點(diǎn)
  size_t size; //記錄單鏈表中的結(jié)點(diǎn)個(gè)數(shù)
}List;
void InitList(List *list);//初始化單鏈表
void push_back(List *list, ElemType x);//在單鏈表的末尾插入元素
void push_front(List *list, ElemType x);//在單鏈表的頭部插入元素
void show_list(List *list);//打印單鏈表
void pop_back(List *list);//刪除單鏈表的最后一個(gè)元素
void pop_front(List *list);//刪除單鏈表的第一個(gè)元素
void insert_val(List *list, ElemType val);//將數(shù)據(jù)元素插入到單鏈表中（要求此時(shí)單鏈表中的數(shù)據(jù)元素順序排列）
Node* find(List *list, ElemType x);//查找單鏈表中數(shù)據(jù)值為x的結(jié)點(diǎn)
int length(List *list);//求單鏈表的長(zhǎng)度
void delete_val(List *list, ElemType x);//按值刪除單鏈表中的某個(gè)數(shù)據(jù)元素
void sort(List *list);//對(duì)單鏈表進(jìn)行排序
void reverse(List *list);//逆置單鏈表
void clear(List *list);//清除單鏈表
void destroy(List *list);//摧毀單鏈表
#endif //__SLIST_H__

#include"slist.h"
void InitList(List *list) {
  list->first = list->last = (Node*)malloc(sizeof(Node)); //頭結(jié)點(diǎn)
  assert(list->first != NULL);
  list->first->next = NULL;
  list->size = 0;
}
void push_back(List *list, ElemType x) {
  //step 1：創(chuàng)建一個(gè)新的結(jié)點(diǎn)
  Node *s = (Node*)malloc(sizeof(Node));
  assert(s != NULL);
  s->data = x;
  s->next = NULL;
  //step 2：將新結(jié)點(diǎn)插入單鏈表的表尾
  list->last->next = s;
  list->last = s;
  //step 3：更新單鏈表的長(zhǎng)度
  list->size++;
}
void push_front(List *list, ElemType x) {
  //step 1：創(chuàng)建一個(gè)新的結(jié)點(diǎn)
  Node *s = (Node*)malloc(sizeof(Node));
  assert(s != NULL);
  s->data = x;
  s->next = NULL;
  //step 2：將新結(jié)點(diǎn)插入單鏈表的表頭
  s->next = list->first->next;
  list->first->next = s;
  //step 3：判斷插入的結(jié)點(diǎn)是否是單鏈表的第一個(gè)結(jié)點(diǎn)，若是更新鏈表的尾指針
  if (list->size == 0)
    list->last = s;
  //step 4：更新單鏈表的長(zhǎng)度
  list->size++;
}
void show_list(List *list) {
  //step 1：指針p指向單鏈表的第一個(gè)結(jié)點(diǎn)
  Node *p = list->first->next;
  //step 2：循環(huán)打印結(jié)點(diǎn)的信息
  while (p != NULL) {
    printf("%d->", p->data);
    p = p->next;
  }
  printf("Nul.\n");
}
void pop_back(List *list) {
  //step 1：判斷單鏈表是否為空
  if (list->size == 0) return;
  //step 2：定義指針p使其指向目標(biāo)結(jié)點(diǎn)的前一個(gè)結(jié)點(diǎn)
  Node *p = list->first;//從頭結(jié)點(diǎn)開(kāi)始
  while (p->next != list->last)
    p = p->next;
  //step 3：刪除目標(biāo)結(jié)點(diǎn)
  free(list->last);
  list->last = p;
  list->last->next = NULL;
  //step 4：更新單鏈表的長(zhǎng)度
  list->size--;
}
void pop_front(List *list) {
  //step 1：判斷單鏈表是否為空
  if (list->size == 0) return;
  //step 2：定義指針p使其指向目標(biāo)結(jié)點(diǎn)的前一個(gè)結(jié)點(diǎn)
  Node *p = list->first->next;
  //step 3：刪除目標(biāo)結(jié)點(diǎn)
  list->first->next = p->next;
  free(p);
  //step 4：判斷刪除的結(jié)點(diǎn)是否是單鏈表的最后一個(gè)結(jié)點(diǎn)，若是則更新單鏈表的尾指針
  if (list->size == 1)
    list->last = list->first;
  //step 4：更新單鏈表的長(zhǎng)度
  list->size--;
}
void insert_val(List *list, ElemType x) {
  //step 1：創(chuàng)建一個(gè)新的結(jié)點(diǎn)
  Node *s = (Node*)malloc(sizeof(Node));
  assert(s != NULL);
  s->data = x;
  s->next = NULL;
  //step 2：定義指針p使其指向待插入位置的前一個(gè)結(jié)點(diǎn)
  Node *p = list->first;//從頭結(jié)點(diǎn)開(kāi)始
  while (p->next != NULL && p->next->data < s->data)
    p = p->next;
  //step 3：判斷結(jié)點(diǎn)的待插入位置是否是表尾，若是則更新單鏈表的尾指針
  if (p->next == NULL)
    list->last = s;
  //step 4：插入結(jié)點(diǎn)
  s->next = p->next;
  p->next = s;
  //step 5：更新單鏈表長(zhǎng)度
  list->size++;
}
Node* find(List *list, ElemType x) {
  //step 1：指針p指向單鏈表的第一個(gè)結(jié)點(diǎn)
  Node *p = list->first->next;
  //step 2：按照循環(huán)順序查找鏈表結(jié)點(diǎn)
  while (p != NULL && p->data != x)
    p = p->next;
  return p;
}
int length(List *list) {
  return list->size;
}
void delete_val(List *list, ElemType x) {
  //step 1：判斷單鏈表是否為空
  if (list->size == 0) return;
  //step 2：確定結(jié)點(diǎn)在單鏈表中的位置，并判斷其是否存在于單鏈表中
  Node *p = find(list, x);
  if (p == NULL) {
    printf("要?jiǎng)h除的數(shù)據(jù)不存在！\n");
    return;
  }
  //step 3：判斷結(jié)點(diǎn)位置是否是表尾
  if (p == list->last)//是表尾
    pop_back(list);
  else {//不是表尾
    Node *q = p->next;
    p->data = q->data;
    p->next = q->next;
    free(q);
    list->size--;
  }
}
void sort(List *list) {
  //step 1：判斷單鏈表中的結(jié)點(diǎn)數(shù)是否為0或1
  if (list->size == 0 || list->size == 1) return;
  //step 2：將單鏈表中第一個(gè)結(jié)點(diǎn)之后的鏈表部分截出，方便重新按順序插入鏈表之中
  Node *s = list->first->next; // 指針s指向單鏈表的第一個(gè)節(jié)點(diǎn)
  Node *p = s->next;//q指向s后面的結(jié)點(diǎn)
  list->last = s;//單鏈表的尾指針指向單鏈表的第一個(gè)結(jié)點(diǎn)
  list->last->next = NULL;//截?cái)噫湵?  //step 3：將截出的鏈表中的結(jié)點(diǎn)根據(jù)其數(shù)據(jù)域大小重新插入到原來(lái)鏈表中
  while (p != NULL) {
    s = p;
    p = p->next;
    Node *q = list->first;
    while (q->next != NULL && q->next->data < s->data)
      q = q->next;
    if (q->next == NULL)//判斷q此時(shí)指向的是否是單鏈表的最后一個(gè)結(jié)點(diǎn)，若是則更新鏈表的尾指針
      list->last = s;
    //將結(jié)點(diǎn)重新插入鏈表
    s->next = q->next;
    q->next = s;
  }
}
void reverse(List *list) {
  //step 1：判斷單鏈表中的結(jié)點(diǎn)數(shù)是否為0或1
  if (list->size == 0 || list->size == 1) return;
  //step 2：將單鏈表中第一個(gè)結(jié)點(diǎn)之后的鏈表部分截出，然后將截出的鏈表中的結(jié)點(diǎn)按頭插法重新插入到原鏈表中
  Node *p = list->first->next;
  Node *q = p->next;
  list->last = p;
  list->last->next = NULL;
  while (q != NULL) {
    p = q;
    q = q->next;
    p->next = list->first->next;
    list->first->next = p;
  }
}
void clear(List *list) {
  //step 1：判斷單鏈表是否為空
  if (list->size == 0) return;
  //step 2：釋放單鏈表中的每一個(gè)結(jié)點(diǎn)
  Node *p = list->first->next;
  while (p != NULL) {
    list->first->next = p->next;
    free(p);
    p = list->first->next;
  }
  //step 3：頭指針和尾指針重新都指向頭結(jié)點(diǎn)
  list->last = list->first;
  //step 4：更新鏈表長(zhǎng)度
  list->size = 0;
}
void destroy(List *list) {
  //step 1：清空單鏈表
  clear(list);
  //step 2：釋放頭結(jié)點(diǎn)
  free(list->first);
  //step 3：頭指針和尾指針都賦值為空
  list->first = list->last = NULL;
}

#include"slist.h"
void main() {
  List mylist;
  InitList(&mylist);
  ElemType item;
  Node *p = NULL;
  int select = 1;
  while (select) {
    printf("*******************************************\n");
    printf("*[1] push_back    [2] push_front  *\n");
    printf("*[3] show_list    [4] pop_back   *\n");
    printf("*[5] pop_front    [6] insert_val  *\n");
    printf("*[7] find       [8] length    *\n");
    printf("*[9] delete_val    [10] sort     *\n");
    printf("*[11] reverse     [12] clear     *\n");
    printf("*[13*] destroy     [0] quit_system  *\n");
    printf("*******************************************\n");
    printf("請(qǐng)選擇：>>");
    scanf("%d", &select);
    if (select == 0) break;
    switch (select) {
    case 1:
      printf("請(qǐng)輸入要插入的數(shù)據(jù)（-1結(jié)束）:>");
      while (scanf("%d", &item), item != -1) {
        push_back(&mylist, item);
      }
      break;
    case 2:
      printf("請(qǐng)輸入要插入的數(shù)據(jù)（-1結(jié)束）:>");
      while (scanf("%d", &item), item != -1) {
        push_front(&mylist, item);
      }
      break;
    case 3:
      show_list(&mylist);
      break;
    case 4:
      pop_back(&mylist);
      break;
    case 5:
      pop_front(&mylist);
      break;
    case 6:
      printf("請(qǐng)輸入要插入的數(shù)據(jù):>");
      scanf("%d", &item);
      insert_val(&mylist, item);
      break;
    case 7:
      printf("請(qǐng)輸入要查找的數(shù)據(jù):>");
      scanf("%d", &item);
      p = find(&mylist, item);
      if (p == NULL)
        printf("要查找的數(shù)據(jù)在單鏈表中不存在！\n");
      break;
    case 8:
      printf("單鏈表的長(zhǎng)度為%d\n", length(&mylist));
      break;
    case 9:
      printf("請(qǐng)輸入要?jiǎng)h除的值:>");
      scanf("%d", &item);
      delete_val(&mylist, item);
      break;
    case 10:
      sort(&mylist);
      break;
    case 11:
      reverse(&mylist);
      break;
    case 12:
      clear(&mylist);
      break;
      //case 13:
      //destroy(&mylist);
      //break;
    default:
      printf("選擇錯(cuò)誤,請(qǐng)重新選擇！\n");
      break;
    }
  }
  destroy(&mylist); //程序結(jié)束，摧毀鏈表
}

#ifndef __SLIST_H__
#define __SLIST_H__
#include<cstdio>
#include<malloc.h>
#include<assert.h>
typedef int ElemType;
typedef struct Node { //定義單鏈表中的結(jié)點(diǎn)信息
  ElemType data; //結(jié)點(diǎn)的數(shù)據(jù)域
  struct Node *next; //結(jié)點(diǎn)的指針域
}Node,*PNode;
typedef struct List { //定義單鏈表的鏈表信息
  PNode first; //first指向單鏈表中的第一個(gè)結(jié)點(diǎn)
  PNode last; //last指向單鏈表中的最后一個(gè)結(jié)點(diǎn)
  size_t size; //記錄單鏈表中的結(jié)點(diǎn)個(gè)數(shù)
}List;
void InitList(List *list);//初始化單鏈表
void push_back(List *list, ElemType x);//在單鏈表的末尾插入元素
void push_front(List *list, ElemType x);//在單鏈表的頭部插入元素
void show_list(List *list);//打印單鏈表
void pop_back(List *list);//刪除單鏈表的最后一個(gè)元素
void pop_front(List *list);//刪除單鏈表的第一個(gè)元素
void insert_val(List *list, ElemType val);//將數(shù)據(jù)元素插入到單鏈表中（要求此時(shí)單鏈表中的數(shù)據(jù)元素順序排列）
Node* find(List *list, ElemType x);//查找單鏈表中數(shù)據(jù)值為x的結(jié)點(diǎn)
int length(List *list);//求單鏈表的長(zhǎng)度
void delete_val(List *list, ElemType x);//按值刪除單鏈表中的某個(gè)數(shù)據(jù)元素
void sort(List *list);//對(duì)單鏈表進(jìn)行排序
void reverse(List *list);//逆置單鏈表
void clear(List *list);//清除單鏈表
void destroy(List *list);//摧毀單鏈表
//代碼優(yōu)化
Node* CreateNode(ElemType x); //創(chuàng)建一個(gè)單鏈表結(jié)點(diǎn)
Node* begin(List *list); //返回單鏈表的第一個(gè)結(jié)點(diǎn)
Node* end(List *list); //返回單鏈表中最后一個(gè)結(jié)點(diǎn)的下一個(gè)結(jié)點(diǎn)
void insert(List *list, Node *pos, ElemType x); //在單鏈表的特定位置（pos）插入新的結(jié)點(diǎn)
#endif //__SLIST_H__

#include"slist.h"
void InitList(List *list) {
  list->first = list->last = (Node*)malloc(sizeof(Node)); //頭結(jié)點(diǎn)
  assert(list->first != NULL);
  list->first->next = NULL;
  list->size = 0;
}
//push_back的優(yōu)化
void push_back(List *list, ElemType x) {
  insert(list, end(list), x);
}
//push_front的優(yōu)化
void push_front(List *list, ElemType x) {
  insert(list, begin(list), x);
}
void show_list(List *list) {
  //step 1：指針p指向單鏈表的第一個(gè)結(jié)點(diǎn)
  Node *p = list->first->next;
  //step 2：循環(huán)打印結(jié)點(diǎn)的信息
  while (p != NULL) {
    printf("%d->", p->data);
    p = p->next;
  }
  printf("Nul.\n");
}
void pop_back(List *list) {
  //step 1：判斷單鏈表是否為空
  if (list->size == 0) return;
  //step 2：定義指針p使其指向目標(biāo)結(jié)點(diǎn)的前一個(gè)結(jié)點(diǎn)
  Node *p = list->first;//從頭結(jié)點(diǎn)開(kāi)始
  while (p->next != list->last)
    p = p->next;
  //step 3：刪除目標(biāo)結(jié)點(diǎn)
  free(list->last);
  list->last = p;
  list->last->next = NULL;
  //step 4：更新單鏈表的長(zhǎng)度
  list->size--;
}
void pop_front(List *list) {
  //step 1：判斷單鏈表是否為空
  if (list->size == 0) return;
  //step 2：定義指針p使其指向目標(biāo)結(jié)點(diǎn)的前一個(gè)結(jié)點(diǎn)
  Node *p = list->first->next;
  //step 3：刪除目標(biāo)結(jié)點(diǎn)
  list->first->next = p->next;
  free(p);
  //step 4：判斷刪除的結(jié)點(diǎn)是否是單鏈表的最后一個(gè)結(jié)點(diǎn)，若是則更新單鏈表的尾指針
  if (list->size == 1)
    list->last = list->first;
  //step 4：更新單鏈表的長(zhǎng)度
  list->size--;
}
//insert_val的優(yōu)化
void insert_val(List *list, ElemType x) {
  //step 1：創(chuàng)建一個(gè)新的結(jié)點(diǎn)
  Node *s = CreateNode(x);
  //step 2：定義指針p使其指向待插入位置的前一個(gè)結(jié)點(diǎn)
  Node *p = list->first;//從頭結(jié)點(diǎn)開(kāi)始
  while (p->next != NULL && p->next->data < s->data)
    p = p->next;
  //step 3：判斷結(jié)點(diǎn)的待插入位置是否是表尾，若是則更新單鏈表的尾指針
  if (p->next == NULL)
    list->last = s;
  //step 4：插入結(jié)點(diǎn)
  s->next = p->next;
  p->next = s;
  //step 5：更新單鏈表長(zhǎng)度
  list->size++;
}
Node* find(List *list, ElemType x) {
  //step 1：指針p指向單鏈表的第一個(gè)結(jié)點(diǎn)
  Node *p = list->first->next;
  //step 2：按照循環(huán)順序查找鏈表結(jié)點(diǎn)
  while (p != NULL && p->data != x)
    p = p->next;
  return p;
}
int length(List *list) {
  return list->size;
}
void delete_val(List *list, ElemType x) {
  //step 1：判斷單鏈表是否為空
  if (list->size == 0) return;
  //step 2：確定結(jié)點(diǎn)在單鏈表中的位置，并判斷其是否存在于單鏈表中
  Node *p = find(list, x);
  if (p == NULL) {
    printf("要?jiǎng)h除的數(shù)據(jù)不存在！\n");
    return;
  }
  //step 3：判斷結(jié)點(diǎn)位置是否是表尾
  if (p == list->last)//是表尾
    pop_back(list);
  else {//不是表尾
    Node *q = p->next;
    p->data = q->data;
    p->next = q->next;
    free(q);
    list->size--;
  }
}
void sort(List *list) {
  //step 1：判斷單鏈表中的結(jié)點(diǎn)數(shù)是否為0或1
  if (list->size == 0 || list->size == 1) return;
  //step 2：將單鏈表中第一個(gè)結(jié)點(diǎn)之后的鏈表部分截出，方便重新按順序插入鏈表之中
  Node *s = list->first->next; // 指針s指向單鏈表的第一個(gè)節(jié)點(diǎn)
  Node *p = s->next;//q指向s后面的結(jié)點(diǎn)
  list->last = s;//單鏈表的尾指針指向單鏈表的第一個(gè)結(jié)點(diǎn)
  list->last->next = NULL;//截?cái)噫湵?  //step 3：將截出的鏈表中的結(jié)點(diǎn)根據(jù)其數(shù)據(jù)域大小重新插入到原來(lái)鏈表中
  while (p != NULL) {
    s = p;
    p = p->next;
    Node *q = list->first;
    while (q->next != NULL && q->next->data < s->data)
      q = q->next;
    if (q->next == NULL)//判斷q此時(shí)指向的是否是單鏈表的最后一個(gè)結(jié)點(diǎn)，若是則更新鏈表的尾指針
      list->last = s;
    //將結(jié)點(diǎn)重新插入鏈表
    s->next = q->next;
    q->next = s;
  }
}
void reverse(List *list) {
  //step 1：判斷單鏈表中的結(jié)點(diǎn)數(shù)是否為0或1
  if (list->size == 0 || list->size == 1) return;
  //step 2：將單鏈表中第一個(gè)結(jié)點(diǎn)之后的鏈表部分截出，然后將截出的鏈表中的結(jié)點(diǎn)按頭插法重新插入到原鏈表中
  Node *p = list->first->next;
  Node *q = p->next;
  list->last = p;
  list->last->next = NULL;
  while (q != NULL) {
    p = q;
    q = q->next;
    p->next = list->first->next;
    list->first->next = p;
  }
}
void clear(List *list) {
  //step 1：判斷單鏈表是否為空
  if (list->size == 0) return;
  //step 2：釋放單鏈表中的每一個(gè)結(jié)點(diǎn)
  Node *p = list->first->next;
  while (p != NULL) {
    list->first->next = p->next;
    free(p);
    p = list->first->next;
  }
  //step 3：頭指針和尾指針重新都指向頭結(jié)點(diǎn)
  list->last = list->first;
  //step 4：更新鏈表長(zhǎng)度
  list->size = 0;
}
void destroy(List *list) {
  //step 1：清空單鏈表
  clear(list);
  //step 2：釋放頭結(jié)點(diǎn)
  free(list->first);
  //step 3：頭指針和尾指針都賦值為空
  list->first = list->last = NULL;
}
//優(yōu)化
Node* CreateNode(ElemType x) {
  Node *s = (Node*)malloc(sizeof(Node));
  assert(s != NULL);
  s->data = x;
  s->next = NULL;
  return s;
}
Node* begin(List *list) {
  return list->first->next;
}
Node* end(List *list) {
  return list->last->next;
}
void insert(List *list, Node *pos, ElemType x) {
  //step 1：創(chuàng)建一個(gè)新的結(jié)點(diǎn)
  Node *s = CreateNode(x);
  //step 2：確定帶插入位置
  Node *p = list->first;
  while (p->next != pos)
    p = p->next;
  //step 3：插入結(jié)點(diǎn)
  s->next = p->next;
  p->next = s;
  //step 4：判斷結(jié)點(diǎn)是否插入到鏈表的表尾，若是則更新單鏈表的表尾指針
  if (pos == NULL)
    list->last = s;
  //step 5：更新單鏈表長(zhǎng)度
  list->size++;
}

#include"slist.h"
void main() {
  List mylist;
  InitList(&mylist);
  ElemType item;
  Node *p = NULL;
  int select = 1;
  while (select) {
    printf("*******************************************\n");
    printf("*[1] push_back    [2] push_front  *\n");
    printf("*[3] show_list    [4] pop_back   *\n");
    printf("*[5] pop_front    [6] insert_val  *\n");
    printf("*[7] find       [8] length    *\n");
    printf("*[9] delete_val    [10] sort     *\n");
    printf("*[11] reverse     [12] clear     *\n");
    printf("*[13*] destroy     [0] quit_system  *\n");
    printf("*******************************************\n");
    printf("請(qǐng)選擇：>>");
    scanf("%d", &select);
    if (select == 0) break;
    switch (select) {
    case 1:
      printf("請(qǐng)輸入要插入的數(shù)據(jù)（-1結(jié)束）:>");
      while (scanf("%d", &item), item != -1) {
        push_back(&mylist, item);
      }
      break;
    case 2:
      printf("請(qǐng)輸入要插入的數(shù)據(jù)（-1結(jié)束）:>");
      while (scanf("%d", &item), item != -1) {
        push_front(&mylist, item);
      }
      break;
    case 3:
      show_list(&mylist);
      break;
    case 4:
      pop_back(&mylist);
      break;
    case 5:
      pop_front(&mylist);
      break;
    case 6:
      printf("請(qǐng)輸入要插入的數(shù)據(jù):>");
      scanf("%d", &item);
      insert_val(&mylist, item);
      break;
    case 7:
      printf("請(qǐng)輸入要查找的數(shù)據(jù):>");
      scanf("%d", &item);
      p = find(&mylist, item);
      if (p == NULL)
        printf("要查找的數(shù)據(jù)在單鏈表中不存在！\n");
      break;
    case 8:
      printf("單鏈表的長(zhǎng)度為%d\n", length(&mylist));
      break;
    case 9:
      printf("請(qǐng)輸入要?jiǎng)h除的值:>");
      scanf("%d", &item);
      delete_val(&mylist, item);
      break;
    case 10:
      sort(&mylist);
      break;
    case 11:
      reverse(&mylist);
      break;
    case 12:
      clear(&mylist);
      break;
      //case 13:
      //destroy(&mylist);
      //break;
    default:
      printf("選擇錯(cuò)誤,請(qǐng)重新選擇！\n");
      break;
    }
  }
  destroy(&mylist); //程序結(jié)束，摧毀鏈表
}