C language single linked list implementation method details
- 2020-06-03 07:59:27
- OfStack
An example of C language single linked list is presented in this paper. To share for your reference, specific as follows:
slist.h
#ifndef __SLIST_H__
#define __SLIST_H__
#include<cstdio>
#include<malloc.h>
#include<assert.h>
typedef int ElemType;
typedef struct Node { // Defines node information in a single linked list
ElemType data; // The data field of a node
struct Node *next; // The pointer field of a node
}Node,*PNode;
typedef struct List { // Defines the list information for a single linked list
PNode first; //first Points to a number in a single linked list 1 A node
PNode last; //last To the end of a single linked list 1 A node
size_t size; // Record the number of nodes in a single linked list
}List;
void InitList(List *list);// Initializes a single linked list
void push_back(List *list, ElemType x);// Inserts elements at the end of a single linked list
void push_front(List *list, ElemType x);// Inserts elements into the header of a single linked list
void show_list(List *list);// Print a single linked list
void pop_back(List *list);// Delete the end of a single linked list 1 An element
void pop_front(List *list);// Deletes a single linked list 1 An element
void insert_val(List *list, ElemType val);// Insert data elements into a single linked list (the data elements in the single linked list are ordered at this point)
Node* find(List *list, ElemType x);// Find the data value in the single linked list x The node
int length(List *list);// Find the length of a single list
void delete_val(List *list, ElemType x);// Deletes a data element from a single linked list by value
void sort(List *list);// Sort a single linked list
void reverse(List *list);// Invert a single linked list
void clear(List *list);// Clear the single linked list
void destroy(List *list);// Destroy the single linked list
#endif //__SLIST_H__
slist.cpp
#include"slist.h"
void InitList(List *list) {
list->first = list->last = (Node*)malloc(sizeof(Node)); // The first node
assert(list->first != NULL);
list->first->next = NULL;
list->size = 0;
}
void push_back(List *list, ElemType x) {
//step 1 : create 1 A new node
Node *s = (Node*)malloc(sizeof(Node));
assert(s != NULL);
s->data = x;
s->next = NULL;
//step 2 : Inserts a new node into the end of a single linked list
list->last->next = s;
list->last = s;
//step 3 : Updates the length of a single linked list
list->size++;
}
void push_front(List *list, ElemType x) {
//step 1 : create 1 A new node
Node *s = (Node*)malloc(sizeof(Node));
assert(s != NULL);
s->data = x;
s->next = NULL;
//step 2 : Inserts a new node into the header of a single linked list
s->next = list->first->next;
list->first->next = s;
//step 3 : Determine whether the inserted node is the first in a single linked list 1 If update the end pointer of the linked list
if (list->size == 0)
list->last = s;
//step 4 : Updates the length of a single linked list
list->size++;
}
void show_list(List *list) {
//step 1 Pointer to: p Points to the end of a single linked list 1 A node
Node *p = list->first->next;
//step 2 : Circulates the information of the print node
while (p != NULL) {
printf("%d->", p->data);
p = p->next;
}
printf("Nul.\n");
}
void pop_back(List *list) {
//step 1 : To determine whether a single linked list is empty
if (list->size == 0) return;
//step 2 : Define pointer p Make it point to the front of the target node 1 A node
Node *p = list->first;// From scratch
while (p->next != list->last)
p = p->next;
//step 3 : Delete the target node
free(list->last);
list->last = p;
list->last->next = NULL;
//step 4 : Updates the length of a single linked list
list->size--;
}
void pop_front(List *list) {
//step 1 : To determine whether a single linked list is empty
if (list->size == 0) return;
//step 2 : Define pointer p Make it point to the front of the target node 1 A node
Node *p = list->first->next;
//step 3 : Delete the target node
list->first->next = p->next;
free(p);
//step 4 : Determine whether the deleted node is the last in a single linked list 1 If so, update the tail pointer of the single linked list
if (list->size == 1)
list->last = list->first;
//step 4 : Updates the length of a single linked list
list->size--;
}
void insert_val(List *list, ElemType x) {
//step 1 : create 1 A new node
Node *s = (Node*)malloc(sizeof(Node));
assert(s != NULL);
s->data = x;
s->next = NULL;
//step 2 : Define pointer p Make it point ahead of the position to be inserted 1 A node
Node *p = list->first;// From scratch
while (p->next != NULL && p->next->data < s->data)
p = p->next;
//step 3 : Determine whether the node to be inserted at the end of the table, if so, update the end pointer of the single linked list
if (p->next == NULL)
list->last = s;
//step 4 : Insert node
s->next = p->next;
p->next = s;
//step 5 : Updates the length of a single list
list->size++;
}
Node* find(List *list, ElemType x) {
//step 1 Pointer to: p Points to the end of a single linked list 1 A node
Node *p = list->first->next;
//step 2 : Search linked list nodes in circular order
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 : To determine whether a single linked list is empty
if (list->size == 0) return;
//step 2 : Determine the position of the node in the single linked list, and judge whether it exists in the single linked list
Node *p = find(list, x);
if (p == NULL) {
printf(" The data to be deleted does not exist! \n");
return;
}
//step 3 : Determine whether the node position is the end of the table
if (p == list->last)// Is the footer
pop_back(list);
else {// Not a footer
Node *q = p->next;
p->data = q->data;
p->next = q->next;
free(q);
list->size--;
}
}
void sort(List *list) {
//step 1 : Determine whether the number of nodes in a single linked list is 0 or 1
if (list->size == 0 || list->size == 1) return;
//step 2 : Will be a single linked list of the number 1 After the node of the linked list section cut out, easy to re-insert the list in order
Node *s = list->first->next; // Pointer to the s Points to the end of a single linked list 1 A node
Node *p = s->next;//q Point to the s Subsequent nodes
list->last = s;// The tail pointer of a singly linked list points to the beginning of the singly linked list 1 A node
list->last->next = NULL;// Truncated list
//step 3 : Insert the node in the truncated list back into the original list according to its data field size
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)// judge q Is it pointing to the end of a single list 1 If so, update the end pointer of the linked list
list->last = s;
// Insert the node back into the list
s->next = q->next;
q->next = s;
}
}
void reverse(List *list) {
//step 1 : Determine whether the number of nodes in a single linked list is 0 or 1
if (list->size == 0 || list->size == 1) return;
//step 2 : Will be a single linked list of the number 1 The section of the linked list after the node is truncated, and then the node in the truncated linked list is re-inserted into the original linked list by the method of header insertion
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 : To determine whether a single linked list is empty
if (list->size == 0) return;
//step 2 : Releases each in a single linked list 1 A node
Node *p = list->first->next;
while (p != NULL) {
list->first->next = p->next;
free(p);
p = list->first->next;
}
//step 3 : Both the head pointer and the tail pointer point to the head again
list->last = list->first;
//step 4 : Updates the list length
list->size = 0;
}
void destroy(List *list) {
//step 1 : Clear a single linked list
clear(list);
//step 2 : Release the head
free(list->first);
//step 3 : Both the head pointer and tail pointer are null
list->first = list->last = NULL;
}
main.cpp
#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(" Please select: >>");
scanf("%d", &select);
if (select == 0) break;
switch (select) {
case 1:
printf(" Please enter the data you want to insert ( -1 The end) :>");
while (scanf("%d", &item), item != -1) {
push_back(&mylist, item);
}
break;
case 2:
printf(" Please enter the data you want to insert ( -1 The end) :>");
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(" Please enter the data to insert :>");
scanf("%d", &item);
insert_val(&mylist, item);
break;
case 7:
printf(" Enter the data you are looking for :>");
scanf("%d", &item);
p = find(&mylist, item);
if (p == NULL)
printf(" The data you are looking for does not exist in a single linked list! \n");
break;
case 8:
printf(" The length of a single linked list is %d\n", length(&mylist));
break;
case 9:
printf(" Please enter the value to delete :>");
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(" The wrong choice , Please choose again! \n");
break;
}
}
destroy(&mylist); // Program over. Destroy the list
}
Attached: Single linked list optimized version
slist.h
#ifndef __SLIST_H__
#define __SLIST_H__
#include<cstdio>
#include<malloc.h>
#include<assert.h>
typedef int ElemType;
typedef struct Node { // Defines node information in a single linked list
ElemType data; // The data field of a node
struct Node *next; // The pointer field of a node
}Node,*PNode;
typedef struct List { // Defines the list information for a single linked list
PNode first; //first Points to a number in a single linked list 1 A node
PNode last; //last To the end of a single linked list 1 A node
size_t size; // Record the number of nodes in a single linked list
}List;
void InitList(List *list);// Initializes a single linked list
void push_back(List *list, ElemType x);// Inserts elements at the end of a single linked list
void push_front(List *list, ElemType x);// Inserts elements into the header of a single linked list
void show_list(List *list);// Print a single linked list
void pop_back(List *list);// Delete the end of a single linked list 1 An element
void pop_front(List *list);// Deletes a single linked list 1 An element
void insert_val(List *list, ElemType val);// Insert data elements into a single linked list (the data elements in the single linked list are ordered at this point)
Node* find(List *list, ElemType x);// Find the data value in the single linked list x The node
int length(List *list);// Find the length of a single list
void delete_val(List *list, ElemType x);// Deletes a data element from a single linked list by value
void sort(List *list);// Sort a single linked list
void reverse(List *list);// Invert a single linked list
void clear(List *list);// Clear the single linked list
void destroy(List *list);// Destroy the single linked list
// Code optimization
Node* CreateNode(ElemType x); // create 1 A single list node
Node* begin(List *list); // Returns the number of a single linked list 1 A node
Node* end(List *list); // Returns the end of a single linked list 1 The number of nodes 1 A node
void insert(List *list, Node *pos, ElemType x); // At a particular location in a single linked list ( pos ) Insert a new node
#endif //__SLIST_H__
slist.cpp
#include"slist.h"
void InitList(List *list) {
list->first = list->last = (Node*)malloc(sizeof(Node)); // The first node
assert(list->first != NULL);
list->first->next = NULL;
list->size = 0;
}
//push_back The optimization of the
void push_back(List *list, ElemType x) {
insert(list, end(list), x);
}
//push_front The optimization of the
void push_front(List *list, ElemType x) {
insert(list, begin(list), x);
}
void show_list(List *list) {
//step 1 Pointer to: p Points to the end of a single linked list 1 A node
Node *p = list->first->next;
//step 2 : Circulates the information of the print node
while (p != NULL) {
printf("%d->", p->data);
p = p->next;
}
printf("Nul.\n");
}
void pop_back(List *list) {
//step 1 : To determine whether a single linked list is empty
if (list->size == 0) return;
//step 2 : Define pointer p Make it point to the front of the target node 1 A node
Node *p = list->first;// From scratch
while (p->next != list->last)
p = p->next;
//step 3 : Delete the target node
free(list->last);
list->last = p;
list->last->next = NULL;
//step 4 : Updates the length of a single linked list
list->size--;
}
void pop_front(List *list) {
//step 1 : To determine whether a single linked list is empty
if (list->size == 0) return;
//step 2 : Define pointer p Make it point to the front of the target node 1 A node
Node *p = list->first->next;
//step 3 : Delete the target node
list->first->next = p->next;
free(p);
//step 4 : Determine whether the deleted node is the last in a single linked list 1 If so, update the tail pointer of the single linked list
if (list->size == 1)
list->last = list->first;
//step 4 : Updates the length of a single linked list
list->size--;
}
//insert_val The optimization of the
void insert_val(List *list, ElemType x) {
//step 1 : create 1 A new node
Node *s = CreateNode(x);
//step 2 : Define pointer p Make it point ahead of the position to be inserted 1 A node
Node *p = list->first;// From scratch
while (p->next != NULL && p->next->data < s->data)
p = p->next;
//step 3 : Determine whether the node to be inserted at the end of the table, if so, update the end pointer of the single linked list
if (p->next == NULL)
list->last = s;
//step 4 : Insert node
s->next = p->next;
p->next = s;
//step 5 : Updates the length of a single list
list->size++;
}
Node* find(List *list, ElemType x) {
//step 1 Pointer to: p Points to the end of a single linked list 1 A node
Node *p = list->first->next;
//step 2 : Search linked list nodes in circular order
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 : To determine whether a single linked list is empty
if (list->size == 0) return;
//step 2 : Determine the position of the node in the single linked list, and judge whether it exists in the single linked list
Node *p = find(list, x);
if (p == NULL) {
printf(" The data to be deleted does not exist! \n");
return;
}
//step 3 : Determine whether the node position is the end of the table
if (p == list->last)// Is the footer
pop_back(list);
else {// Not a footer
Node *q = p->next;
p->data = q->data;
p->next = q->next;
free(q);
list->size--;
}
}
void sort(List *list) {
//step 1 : Determine whether the number of nodes in a single linked list is 0 or 1
if (list->size == 0 || list->size == 1) return;
//step 2 : Will be a single linked list of the number 1 After the node of the linked list section cut out, easy to re-insert the list in order
Node *s = list->first->next; // Pointer to the s Points to the end of a single linked list 1 A node
Node *p = s->next;//q Point to the s Subsequent nodes
list->last = s;// The tail pointer of a singly linked list points to the beginning of the singly linked list 1 A node
list->last->next = NULL;// Truncated list
//step 3 : Insert the node in the truncated list back into the original list according to its data field size
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)// judge q Is it pointing to the end of a single list 1 If so, update the end pointer of the linked list
list->last = s;
// Insert the node back into the list
s->next = q->next;
q->next = s;
}
}
void reverse(List *list) {
//step 1 : Determine whether the number of nodes in a single linked list is 0 or 1
if (list->size == 0 || list->size == 1) return;
//step 2 : Will be a single linked list of the number 1 The section of the linked list after the node is truncated, and then the node in the truncated linked list is re-inserted into the original linked list by the method of header insertion
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 : To determine whether a single linked list is empty
if (list->size == 0) return;
//step 2 : Releases each in a single linked list 1 A node
Node *p = list->first->next;
while (p != NULL) {
list->first->next = p->next;
free(p);
p = list->first->next;
}
//step 3 : Both the head pointer and the tail pointer point to the head again
list->last = list->first;
//step 4 : Updates the list length
list->size = 0;
}
void destroy(List *list) {
//step 1 : Clear a single linked list
clear(list);
//step 2 : Release the head
free(list->first);
//step 3 : Both the head pointer and tail pointer are null
list->first = list->last = NULL;
}
// To optimize the
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 : create 1 A new node
Node *s = CreateNode(x);
//step 2 : Determine the insertion location of the tape
Node *p = list->first;
while (p->next != pos)
p = p->next;
//step 3 : Insert node
s->next = p->next;
p->next = s;
//step 4 : Determines whether a node is inserted into the end of a linked list. If so, update the end pointer of a single linked list
if (pos == NULL)
list->last = s;
//step 5 : Updates the length of a single list
list->size++;
}
main.cpp
#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(" Please select: >>");
scanf("%d", &select);
if (select == 0) break;
switch (select) {
case 1:
printf(" Please enter the data you want to insert ( -1 The end) :>");
while (scanf("%d", &item), item != -1) {
push_back(&mylist, item);
}
break;
case 2:
printf(" Please enter the data you want to insert ( -1 The end) :>");
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(" Please enter the data to insert :>");
scanf("%d", &item);
insert_val(&mylist, item);
break;
case 7:
printf(" Enter the data you are looking for :>");
scanf("%d", &item);
p = find(&mylist, item);
if (p == NULL)
printf(" The data you are looking for does not exist in a single linked list! \n");
break;
case 8:
printf(" The length of a single linked list is %d\n", length(&mylist));
break;
case 9:
printf(" Please enter the value to delete :>");
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(" The wrong choice , Please choose again! \n");
break;
}
}
destroy(&mylist); // Program over. Destroy the list
}
I hope this article has been helpful in C programming.