Linear chain List of lead nodes in practical application

/*======== the linear list type of the lead node =========*/typedef char elemtype//node type typedef struct lnode{char data; struct Lnode *next;} *link,*position;    List type typedef struct{link head,tail; int Len;}  linklist; /*======================================================*//*======= Some functions that are called in other function definitions ===============*//*=========  =============================================*//*---Compare---compare the size relationship of two elements */int compare (char A,char b) {return a-A;}        /*---Visit---*/int visit (Link p) {if (...)    return 1;     else return 0;    }/*---length---to find the lengths of the chain */int length (link s) {int i=0;    Link P=null;    P=s;        while (p->next!=null) {p=p->next;    i++; } return i;}    /*---Print---all elements of the list are printed on the screen */void print (linklist L) {link p=null;    P=l.head;        if (!p->next) {printf ("\nthe linklist is empty.\n\n");    return;    } printf ("The List:");        while (p) {printf ("%c-", p->data);    p=p->next; }} /*======================================================*//*========== definition of a function that operates on a single-chain linear table with a leading node ==*//*===============================================    =======*//*---Assigns a node that is pointed to by P and assigns the value e---*/position makenode (elemtype e) {Link p=null;    p= (Lnode) malloc (sizeof (struct));        if (p) {p->data=e;    p->next=null;    } else return; return p;}  /*---Release P points to the node-*/void freenode (link p) {free (p);} /*---Constructs an empty linear table-*/void initlist (linklist *l) {l->head=makenode (' l ') pointed by L;//Generate Header node l->head->next=null;/*    Not l->head=null*/l->tail=l->head;. l->len=0;}    /*----------Destroy the linear table pointed by L---------*/void destroylist (linklist *l) {Link p;    P= (*l). Tail;        while (p!= (*l). Head) {p=priorpos (*l,p);    Freenode (P->next); } freenode ((*l). Head);}    /* Place the Linear table L as an empty table and release the head node of the original list */void clearlist (linklist *l) {link p;    P= (*l). Tail;        while (p!= (*l). Head) {p=priorpos (*l,p);    Freenode (P->next); } freenode ((*l). Head);} /*---Insert the node that s points toLinear list before the first node-*/void Insfirst (linklist *l,link s) {s->next=l->head->next; if (!       L->head->next) l->tail=s;    /* When performing this operation to an empty linear table */l->head->next=s; l->len++;} /*---Delete the first node in the table and return with Q-*/void delfirst (linklist *l,link q) {if (! L->head->next) {printf ("\nthe linklist is empty,can not delete:        \ n ");    return 0;    } q=l->head->next; L->head->next=l->head->next->next;}    /*---Link a string of nodes in the pointer s to the last node of the linear table L-*/void Append (linklist *l,link s) {link q;    q=l->head; if (!        L->tail) {/* take into account that the list is empty */l->head->next=s;    while (q->next) q=q->next;/* tail node processing */l->tail=q;    } l->tail->next=q=s;    while (Q->next) q=q->next;/* can not forget the processing of the tail node */l->tail=q; L->len+=length (s);} /*---Delete the tail node in the linear table L-*/void Remove (linklist *l,link q) {if (! L->tail) {printf ("\nthe linklist is Empty,can not remonde..        \ n "); return 0;                          } q=l->tail;    L->tail=priorpos (*L,Q); L->tail->next=null;}    /*----*/void insbefore (linklist *l,link p,link s) {link q) before inserting the node pointed by S into the node indicated by P;    Q=priorpos (*L,P);    s->next=p; Q->next=s;}    /*----*/void insafter (linklist *l,link p,link s) after inserting the points pointed to by P into the node indicated by the point "{s->next=p->next; P->next=s;} /*---Use e to update the current node-*/void setcurelem (link p,elemtype e) {p->data=e;}/*---Return the value of the element in the node referred to in P-*/elemtype Getcurele  M (Link p) {return p->data;}    int Listempty (linklist L) {/*---returns 1 if the linear table is empty table, otherwise returns 0-*/if (L.head==l.tail) return 1;  return 0;}  int Listlength (linklist L) {/*---Returns the number of elements in the linear table-*/return l.len;}  Position GetHead (linklist l) {/*---Returns the position of the head node in the linear table L-*/return l.head;}  Position GetLast (linklist l) {/*-----Returns the position of the last node in the linear table l-------*/return l.tail;    /*---Returns the position of the direct precursor of the node referred to in P-*/position priorpos (linklist l,link p) {Link q;    Q=l.head; if (q->next==p) return0;    while (q->next!=p) q=q->next; return q;}    /*-----Returns the position of the direct successor of the point indicated by P-------*/position nextpos (link p) {link q;    q=p->next; return q;}    /*-----Return the position of the first node in the linear table L with P and return to OK-------*/void Locatepos (linklist l,int i,link p) {p=l.head; if (i<=0| |    I>listlength (L)) return 0;        while (i) {p=p->next;    i--;    }/*----Returns the first node order position in the table that satisfies a certain function relationship with E----*/int Locatelem (linklist l,elemtype e) {int i=0;    Link p;    p=l.head->next;        while (compare (p->data,e) &&p) {p=p->next;    ++i;        if (!p) {/* takes into account the case where the specified element is not found */printf ("\nthere ' s no '%c ' in this linklist.", e);    return 0; } return i;}    /*----Use a function to traverse all nodes in the table-------*/void listtraverse (linklist L) {Link p;    P=l.head;   while (!visit (p)) p=p->next; }

Arranges elements of a single-stranded linear table, LA and lb, by value non-descending

Status mergelist_l (nlinklist &la, Nlinklist &lb, nlinklist &lc, int (*compare) (Elemtype, El    Emtype)) {//algorithm 2.21//The elements of the single-chain linear table LA and LB are known to be non-descending by value.    The elements that merge LA and lb to get new single-stranded linear table LC,LC are also non-descending by value.    Nlink ha, HB;    Position PA, Pb, q;    Elemtype A, B; if (!  Initlist (Lc)) return ERROR;      Storage space allocation Failure ha = GetHead (La);    Ha and HB point to the head node of LA and Lb respectively HB = gethead (lb);  PA = Nextpos (La, ha);    PA and PB respectively point to LA and Lb in the current node PB = Nextpos (Lb, HB);  while (PA && pb) {//LA and LB are non-null a = Getcurelem (PA);        A and B are the current comparison elements in two tables B = Getcurelem (PB);  if ((*compare) (A, b) <=0) {//A≤b Delfirst (ha, q);  Append (Lc, q);          PA = Nextpos (La, PA);  } else {//A>b Delfirst (HB, q);  Append (Lc, q);          PB = Nextpos (Lb, PB);        }}//While if (PA) Append (Lc, PA);        Link La remaining nodes else Append (Lc, PB);       Link the remaining node freenode (ha) in lb;      Freenode (HB);        Release the head node of LA and LB return OK;} mergelist_l

Linear chain List of lead nodes in practical application