C and Pointer 12th chapter structure exercises

12.3 Rewrite 12.7, using the head and tail pointers, respectively, to pass to the function as a single pointer, rather than as part of a node

#include <stdio.h> #include <stdlib.h> TRUE 1#define FALSE 0//pointer fwd points to the previous node, BWD points to the latter node typedef struct    Node {struct node *fwd;    struct NODE *bwd; int value;} node;/* pointer to the pointer to the head and tail nodes, four cases * inserted into the header, * inserted into the footer, * inserted into the empty table, * inserted into the table, the first three need to modify the headptr or tailptr pointer */int doublelinklistinsert (N    Ode **headptr, node **tailptr, int value) {node *this = *headptr;    Node *newnode;    while (This! = NULL && This, value < value) {this = this = FWD;    } NewNode = (node *) malloc (sizeof (node));    NewNode, value = value;            if (this = NULL) {//Insert to footer, or empty table if (this = = *headptr) {//INSERT into empty table *headptr = NewNode;            *tailptr = NewNode;            NewNode, fwd = NULL;        NewNode-BWD = NULL;            }else{//Insert to the end of the table newNode, fwd = NULL;            The original footer element is the front node of the current node NewNode-BWD = *tailptr;            (*tailptr), fwd = NewNode; Update tail node pointer *tailPTR = NewNode;            }}else{//INSERT into the header, or the table if (this = = *headptr) {//INSERT into the header newNode-bwd = NULL;            The original table head becomes the second node newNode, fwd = *headptr;            (*headptr), bwd = NewNode;        Update table Header *headptr = NewNode;            }else{//Insert to non-empty table in front of this position newNode, fwd = this;            NewNode-BWD = BWD;            This, bwd, fwd = NewNode;        This, BWD = NewNode; }} return TRUE;    int main () {Node third;    Node second;    Node first;    Third = (Node) {NULL, &second, 4};    Second = (Node) {&third, &first, 2};    First = (Node) {&second, NULL, 1};    Node *head = &first;    Node *tail = &third;    Doublelinklistinsert (&head, &tail, 35);    Doublelinklistinsert (&head, &tail, 3);    Doublelinklistinsert (&head, &tail,-10);    Node *rootptr = head; while (rootptr! = NULL) {printf ("%D\t ", rootptr-value);    Rootptr = Rootptr, fwd; } return 0;}

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12.4 Write functions reverse-order all nodes of a single-linked list.

#include <stdio.h> #include <stdlib.h> #define TRUE 1#define FALSE 0typedef struct Node {struct node *next; int value;} linklist;    Linklist *sll_reverse (linklist *first) {if (first = = null) {return null;    } linklist *current = First;    Linklist *next;    Linklist *pre;    linklist *morepre = NULL;        while (next = current, next) = NULL) {//loop to move the node that is currently pointing to Pre = present;        current = next;        The next pointer of the previous node is modified by the previous node pre-and next = Morepre;    Morepre pointer morepre = Pre before moving the front node;    }//If the IF (current = = first) is returned between the individual nodes {return first;        }else{//modifies the last node pointer, as the head pointer returns the position of the last node, current, next = pre;    return current;    }}int Main () {linklist third = {NULL, 4};    linklist second = {&third, 3};    Linklist first = {&second, 2};    linklist *head = &first;    Head = Sll_reverse (head);        while (head! = NULL) {printf ("%d\t", head-and-value); Head = HeadNext } return 0;}

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12.5 Write a program, remove a node from a single linked list, the first parameter is a pointer to a pointer to the head of the list

#include <stdio.h> #include <stdlib.h> #define TRUE 1#define FALSE 0typedef struct Node {struct node *next; int value;}    linklist;//Remove node Nodeint sll_delete (linklist **first, linklist *node) from the linked list pointed to by first, {linklist **ptr = first;    PTR is a pointer to the next field while (*ptr! = NULL && *ptr! = node) {ptr = & ((*ptr), next);    }//If not found if (*ptr = = NULL) {return FALSE;    }else{//If found, the pre-change node points to *ptr = (*ptr), next; Release node memory free (*PTR);
return FALSE;    }}int Main () {linklist third = {NULL, 3};    linklist second = {&third, 2};    Linklist first = {&second, 1};    linklist *headptr = &first;    linklist *head = headptr;        while (head! = NULL) {printf ("%d\t", head-and-value);    Head = head Next;    } printf ("\ n");    Sll_delete (&headptr, &second);    head = headptr;        while (head! = NULL) {printf ("%d\t", head-and-value);    Head = head Next;    } printf ("\ n");    Sll_delete (&headptr, &first);    head = headptr;        while (head! = NULL) {printf ("%d\t", head-and-value);    Head = head Next;    } printf ("\ n");    Sll_delete (&headptr, &third);    head = headptr;        while (head! = NULL) {printf ("%d\t", head-and-value);    Head = head Next; } return 0;}

　　

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12.6 The node is removed from the doubly linked list, and the first parameter is a pointer to the head of the linked list,

#include <stdio.h> #include <stdlib.h> #define TRUE 1#define FALSE 0typedef struct Node {struct node *next; int value;}    linklist;//Remove node Nodeint sll_delete (linklist *first, linklist *node) from the linked list pointed to by first, {linklist *pre = NULL;    linklist *cur = First;        while (cur = NULL && cur! = node) {pre = cur;    cur = cur next;    }//If not found if (cur = = NULL) {return FALSE;        }else if (cur = = first) {//At this point a value is passed in, only the value pointed to by the head pointer can be modified, modified to the second node *first = * (cur, next);        Free (node);    return TRUE;        }else{Pre, next = cur next;        Free (node);    return TRUE;    }}int Main () {linklist third = {NULL, 3};    linklist second = {&third, 2};    Linklist first = {&second, 1};    linklist *headptr = &first;    linklist *head = headptr;        while (head! = NULL) {printf ("%d\t", head-and-value);    Head = head Next;    } printf ("\ n");    Sll_delete (Headptr, &second);head = headptr;        while (head! = NULL) {printf ("%d\t", head-and-value);    Head = head Next;    } printf ("\ n");    Sll_delete (Headptr, &first);        while (headptr! = NULL) {printf ("%d\t", headptr-value);    Headptr = Headptr Next;    } printf ("\ n");    Sll_delete (Headptr, &third);    head = headptr;        while (head! = NULL) {printf ("%d\t", head-and-value);    Head = head Next;    } printf ("\ n"); return 0;}

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12.7 Creating a Word Index Table

C and Pointer 12th chapter structure exercises