Chain Queue-C language version

Source file part: The pointer did not learn the classmate is very difficult to understand ^_^, a bit chaotic, hope to everyone a little help. #include <stdio.h> #include <malloc.h> #include <stdlib.h> #include <string.h>typedef int Elemtype; #include "LQueue.h" int main () {Deque head;instruction (head); return 0;} Header file section: typedef struct QUEUE{ELEMTYPE data;struct Queue *next;} Lqnode,*lqueue;typedef Struct{lqnode *front; Lqnode *rear;} Deque;void init_queue (Deque *head)//initialize + purge operation = = In fact, the emptying here refers to the node after the head node is discarded {Lqnode *p=null;p= (lqueue) malloc (sizeof (Lqnode )); head->front=p;head->rear=p;p->next=null;} int Empty_queue (Deque *head)//Empty {if (head->front->next==head->rear->next) return 1;return 0;} int Lenght_queue (Deque arrow) {lqnode *p=null;int len=0;p=arrow.front->next;while (p) {len++;p =p->next;} return Len;} void Enqueue (Deque *arrow,elemtype e)//queue operation {Lqueue p=null;p= (lqueue) malloc (sizeof (Lqnode)); if (!p) {printf ("no more CDs !\n "); return;}                 p->data=e;p->next=null;  When inserting, the team first pointer is not required to move the arrow->rear->next=p;arrow->rear=p; RetuRN;} void Dequeue (Deque *arrow,elemtype *e)//outbound operation {Lqnode *p=null;if (Empty_queue (arrow)) {printf ("The current chain queue is empty and the outbound operation cannot be completed!!! \ n "); return;} p=arrow->front->next; (*e) =p->data;arrow->front->next=p->next;printf ("element%d has exited queue!!!                       \ n ", *e); if (Lenght_queue (*arrow) ==0) return; When the last element is dequeue, Arrow->rear does not know where it points to free (p); return;} int Queue_top (Deque *arrow)//return team first element {if (Empty_queue (arrow)) {printf ("The current chain queue is empty, the first element of the team does not exist!!! \ n "); return 0;} printf ("Current team first element is:%d\n", arrow->front->next->data);} void Destroy_queue (Deque *arrow)//The destruction of the chain queue {Lqnode *p=null;if (Empty_queue (arrow)) {printf ("The current chain queue is empty, no destroy operation is required!!! \ n "); return;} while (Arrow->front->next) {p=arrow->front->next;arrow->front->next=p->next;if (Lenght_queue      (*arrow) ==0) break; Free (p);} printf ("Destruction succeeded!\n"); return;} void Print_queue (Deque arrow) {Lqnode *p=null;p=arrow.front->next;while (p) {printf ("%d", P->data);p =p->next ;} printf ("\ n");} void Modify_queue (Deque *arrow,elemtype Index,elemtypee)//modify function {int i=0; Lqnode *p=null;p=arrow->front->next;while (i<index-1) {p=p->next;} p->data=e;printf ("Modified operation completed!\n");} int Insearch_queue (Deque arrow,elemtype e)//Lookup function {lqnode *p=null;int i=1;if (Empty_queue (&arrow)) {printf ("current chain The queue is empty and there are no elements to find!!! \ n "); return 0;} P=arrow.front->next;while (p!=null) {if (e==p->data) {return i;break;} i++;p =p->next;} if (p==null) printf ("Lookup failed, no element exists in the queue!\n"); return 0;} void instruction (Deque head) {int n,m,t,a,b,len1,index;printf ("\t\t1, queue initialization \ n");p rintf ("\t\t2, new queue element \ n");p rintf ("\ t \T3, return team first element \ n ");p rintf (" \t\t4, element out queue \ n ");p rintf (" \t\t5, find queue element \ n ");p rintf (" \t\t6, modify queue element \ n ");p rintf (" \t\t7, destroy queue \ n ") ;p rintf ("\t\t8, queue Length \ n");p rintf ("\t\t9, print queue element \ n");p rintf ("\t\t10, exit program \ n");p rintf ("Please enter the command you need to complete: \ n");d o{scanf ( "%d", &n); if (n<1| | N&GT;10) printf ("Sorry, the instruction number you entered is invalid, please re-enter!!! \ n ");} while (n<1| | N&GT;10), switch (n) {case 1:init_queue (&head);p rintf ("completed chain queue initialization, enter the number of elements you want to add!\n"); scanf ("%d", &n); while ( n--) {int x;scanf ("%d", &x); EnqueuE (&head,x);} printf ("Complete the Build Operation!\n"), Break;case 2:printf ("Enter the number of elements you want to add!\n"), scanf ("%d", &n), while (n--) {int x;scanf ("%d", &x ); Enqueue (&head,x);} printf ("Add success!\n"), Break;case 3:queue_top (&head); Break;case 4:dequeue (&head,&t); Break;case 5:printf (" Please enter the element you are looking for: \ n "), scanf ("%d ", &m), Index=insearch_queue (head,m), and if (index) printf (" The element you are looking for is located in the first%d position of the queue!!! \ n ", index); break;case 6:printf (" Enter the queue position of the element you changed: \ n ");d o{scanf ("%d ", &a); if (a<1| | A>lenght_queue (head) printf ("Sorry, the element you entered is not in the area, please re-enter!!! \ n ");} while (a<1| | A>lenght_queue (head));p rintf ("Please enter the modified value: \ n"); scanf ("%d", &b); Modify_queue (&head,a,b); Break;case 7:destroy_queue (&head) break;case 8:len1=lenght_queue (head);p rintf (" The current chain queue length is:%d\n ", len1); Break;case 9:print_queue (head); Break;case 10:return;default:instruction (head); break;} Instruction (head);}

Chain Queue-C language version