c/c++ 線性表之單向迴圈連結串列

c/c++ 線性表之單向迴圈連結串列

線性表之單向迴圈連結串列

不是存放在連續的記憶體空間，連結串列中的每個節點的next都指向下一個節點，最後一個節點的下一個節點不是NULL，而是頭節點。因為頭尾相連，所以叫單向迴圈連結串列。

真實的第一個節點是頭節點，頭節點不存放資料，單純為了編寫程式方便。但是下面註釋裡寫的【第一個節點】的含義是頭節點的下一節點，也就是真實存放資料的第一個節點。

下面的程式碼實現了以下功能

函式	功能描述
push_back	從連結串列的最後插入節點
push_front	從連結串列的起始插入節點
show_list	列印出連結串列裡每個節點的值
pop_back	刪除連結串列最後一個節點
pop_front	刪除連結串列起始節點
insert_val	在合適的位置插入一個節點； 比如原來的連結串列:1->3->NULL，當要插入的節點的值為2的時候，就會在1和3之間插入這個節點，插入後的連結串列：1->2->3->NULL
find	查詢指定的節點
length	返回連結串列中節點的個數
delete_val	刪除指定的節點
sort	排序，重新排列節點
resver	按倒序，重新排列節點
clear	釋放除了頭節點之外的所有節點所佔用的記憶體空間
destroy	釋放所有節點的所佔用的記憶體空間，包括頭節點

whilenode.h

#ifndef __SEQNODE__
#define __SEQNODE__

#include <stdio.h>
#include <malloc.h>
#include <assert.h>
#include <memory.h>
#include <stdbool.h>

#define ElemType int

typedef struct Node{
  ElemType data;
  struct Node* next;
}Node;

typedef struct NodeList{
  Node*  first;
  Node*  last;
  size_t size;
}NodeList;

void init(NodeList*);
void push_back(NodeList*, ElemType);
void push_front(NodeList*, ElemType);
void pop_back(NodeList*);
void pop_front(NodeList*);
void show_list(NodeList*);
void insert_val(NodeList*, ElemType);
Node* find(NodeList*, ElemType);
void delete_val(NodeList*, ElemType);
void sort(NodeList*);
void sort1(NodeList*);
void resver(NodeList*);
void resver1(NodeList*);
void resver2(NodeList*);
void clear(NodeList*);
void destroy(NodeList*);

#endif

whilenode.c

#include "seqnode.h"

void init(NodeList* list){
  list->first = (Node*)malloc(sizeof(Node));
  list->last = list->first;
  list->last->next = NULL;
  list->size = 0;
}

Node* create_node(ElemType val){
  Node* node = (Node*)malloc(sizeof(Node));
  assert(NULL != node);
  node->data = val;
  node->next = NULL;
  return node;
}
void push_back(NodeList* list, ElemType val){
  Node* p = create_node(val);

  list->last->next = p;
  list->last = p;
  list->last->next = list->first;
  list->size++;
}

void push_front(NodeList* list, ElemType val){
  Node* p = create_node(val);

  p->next = list->first->next;
  list->first->next = p;
  if(list->size == 0){
    list->last = p;
    list->last->next = list->first;
  }
  list->size++;
}

void show_list(NodeList* list){
  Node* tmp = list->first->next;
  while(tmp != list->first){
    printf("%d->", tmp->data);
    tmp = tmp->next;
  }
  printf("NULL
");
}

void pop_back(NodeList* list){
  if(list->size == 0)return;
  Node* p = list->first;
  while(p->next != list->last){
    p = p->next;
  }
  p->next = list->first;
  free(list->last);
  list->last = p;
  list->size--;
}
void pop_front(NodeList* list){
  if(list->size == 0)return;
  Node* p = list->first->next;
  list->first->next = p->next;
  if(list->size == 1){
    list->last = list->first;
  }
  list->size--;
  free(p);
}
void insert_val(NodeList* list, ElemType val){
  if(list->size == 0){
    push_back(list, val);
    return;
  }
  Node* p = create_node(val);

  Node* t = list->first;
  while(t->next != list->first && val > t->next->data){
    t = t->next;
  }
  if(t->next == list->first){
    list->last = p;
  }
  p->next = t->next;
  t->next = p;
  
  list->size++;
}
//尋找目標節點
Node* find(NodeList* list, ElemType val){
  if(0 == list->size){
    return NULL;
  }
  Node* p = list->first->next;
  do{
    if(val == p->data){
      return p;
    }
    p = p->next;
  }
  while(list->first != p);
  return NULL;
}
//尋找目標節點的前一個節點
Node* find1(NodeList* list, ElemType val){
  if(0 == list->size){
    return NULL;
  }
  Node* p = list->first;
  do{
    if(p->next->data == val){
      return p;
    }
    p = p->next;
  }while(list->first != p);
  return NULL;
}
void delete_val(NodeList* list, ElemType val){
  if(0 == list->size)return;
 
  Node* p = find1(list, val);
  if(NULL == p)return;
  if(p->next == list->last){
    list->last = p;
  }
  Node* tmp = p->next;
  p->next = p->next->next;
  free(tmp);
  list->size--;
}

void sort(NodeList* list){
  if(list->size == 0 || list->size == 1)return;

  Node* p = list->first->next;

  Node* t = list->last = list->first;
  list->last->next = list->first;

  size_t s = list->size;

  while(s-- > 0){
    while(p->data > t->next->data && t->next != list->first){
      t = t->next;
    }
    if(t->next == list->first){
      list->last = p;
    }

    Node* tmp = p->next;
    p->next = t->next;
    t->next = p;

    p = tmp;
    t = list->first;
  }
  list->last->next = list->first;
}
void resver(NodeList* list){
  if(list->size == 0 || list->size == 1)return;

  Node* head = list->first->next;
  Node* end = head;

  list->last = list->first;
  list->last->next = list->first;
  
  while(head != list->first){
    Node* tmp = head->next;
  
    head->next = list->first->next;
    list->first->next = head;
    
    head = tmp;
  }
  list->last = end;
}

void clear(NodeList* list){
  if(list->size == 0) return;
  Node* b = list->first->next;
  Node* q;
  while(b != list->first){
    q = b->next;
    free(b);
    b = q;
  }
  list->last = list->first;
  list->last->next = list->first;
  list->size = 0;
}

void destroy(NodeList* list){
  Node* b = list->first;
  Node* q;
  while(b != list->first){
    q = b->next;
    free(b);
    b = q;
  }
}

whilenodemain.c

#include "seqnode.h"

int main(){
  NodeList list;
  init(&list);
  int select = 1;
  ElemType item;
  Node* node = NULL;
  while(select){
    printf("*****************************************
");
    printf("*** [1]   push_back   [2]  push_front ***
");
    printf("*** [3]   show_list   [4]  pop_back   ***
");
    printf("*** [5]   pop_front   [6]  insert_val ***
");
    printf("*** [7]   find        [8]  length     ***
");
    printf("*** [9]   delete_val  [10] sort       ***
");
    printf("*** [11]  sort        [12] resver     ***
");
    printf("*** [13]              [14] clear      ***
");
    printf("*** [0]   quit        [15*]destroy    ***
");
    printf("*****************************************
");
    printf("請選擇:>");
    scanf("%d", &select);
    if(0 == select)
      break;
    switch(select){
    case 1:
      printf("請輸入要插入的資料,以-1結束>
");
      while(scanf("%d",&item) && item != -1){
    push_back(&list, item);
      }
      show_list(&list);
      break;
    case 2:
      printf("請輸入要插入的資料,以-1結束>
");
      while(scanf("%d", &item) && item != -1){
    push_front(&list, item);
      }
      show_list(&list);
      break;
    case 3:
      show_list(&list);
      break;
    case 4:
      pop_back(&list);
      show_list(&list);
      break;
    case 5:
      pop_front(&list);
      show_list(&list);
      break;
    case 6:
      printf("請輸入要插入的資料>
");
      scanf("%d",&item);
      insert_val(&list, item);
      show_list(&list);
      break;
    case 7:
      printf("please enter what you shoule find out>
");
      scanf("%d",&item);
      node = find(&list, item);
      if(node == NULL){
    printf("can not find %d
", item);
      }
      break;
    case 8:
      printf("length is %ld
", list.size);
      break;
    case 9:
      printf("please enter what you want to delete>
");
      scanf("%d",&item);      
      delete_val(&list, item);
      show_list(&list);
      break;
    case 10:
      // sort(&list);
      //show_list(&list);
      break;
    case 11:
      sort(&list);
      show_list(&list);
      break;
    case 12:
      resver(&list);
      show_list(&list);
      break;
    case 13:
      resver(&list);
      show_list(&list);
      break;
    case 14:
      clear(&list);
      show_list(&list);
      break;
    case 15:
      destroy(&list);
      break;
    default:
      break;
    }
  }

  destroy(&list);
}