《C语言课程设计案例精编》课件 6.pptVIP

Basic operations about linked list: 6.7 Basics of Linked List (con.) Building a linked list Calculating the length of a list Inserting an item into a linked list deleting an item from a linked list Accessing all nodes of a list Step I: allocate the storage for the head node. NODE *p; p = (NODE *) malloc (sizeof (NODE)); /* apply a head node p*/ p - link = NULL; /* the next pointer (link) is NULL (empty) */ head = p; /* header pointer points to the head node p*/ Building a linked list Header pointer NULL p Head node Step II: insert node with data into list. First node: NODE * p; p = ( NODE * ) malloc ( sizeof (NODE)); /* apply a node p with data */ gets ( p-name ); /* store the data into the node p points to*/ p-link=head-link; /*store the link of head node into link of node p*/ head-link = p; /*put node p behind head node*/ Header pointer p Head node NULL name NULL Next node: p = ( NODE * ) malloc ( sizeof (NODE)); /* apply a new node p with data */ gets ( p-name ); /* store the data into the node p points to*/ p-link=head-link; /*store the link of head node into link of node p*/ head-link = p; /*put node p behind head node*/ Step II: insert node with data into list (con.). Header pointer p Head node name1 NULL name2 X Assume: there exists a head node, design a function to build a linked list with n nodes (with data). create (NODE * head, int n) { NODE * p; for( ; n0; n--) { p = (NODE *) malloc (sizeof (NODE) ) ; gets (p - name) ; p - link = head - link ; head - link = p ; } } Calculating the length of a list Length of a list is the number of nodes (with data) in the linked list. length ( NODE * head ) { int len; NODE * p; for ( len=0, p = head-link; p!=NULL; len++) p = p-link; /* p points to the next node*/ return ( len ); } Header pointer name NULL Head node Header pointer NULL Head node output ( NODE * head ) { NODE * p; p = head-link; /* point to the first node */ while ( p!=NULL ) { puts (