[linear table] basic operation of bidirectional linked list specify node exchange

Catalog

1. Basic operation of double linked list

2. Creation and printing of bidirectional linked list

3. The specified value is x The node of is exchanged with its predecessor node

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1. Basic operation of double linked list

#include <iostream>
using namespace std;

typedef int Elemtype;
typedef struct LinkNode {
    Elemtype data;
    LinkNode *next, *previous;
} * DLIST, *Node;

void Delete(Node p)
{ // Delete p node 
    if (p->previous != NULL) {
        p->previous->next = p->next;
    }
    if (p->next != NULL) {
        p->next->previous = p->previous;
    }
    delete p;
}

void MakeNull(DLIST &DL)
{ //  Empty the bidirectional linked list 
    delete DL->next;
    DL = new LinkNode;
    DL->next = NULL;
    DL->previous = NULL;
}

void Insert(Elemtype x, Node p)
{ // At node p Add node after q
    Node q = new LinkNode;
    q->data = x;
    q->next = p->next;
    p->next->previous = q;
    p->next = q;
    q->previous = p;
}

Node Locate(Elemtype x, DLIST DL)
{ // Locate the first value as x The elements of 
    Node p = DL;
    while (p->next != NULL) {
        if (p->next->data == x)
            return p->next;
        else
            p = p->next;
    }
    return p->next;
}

2. Creation and printing of bidirectional linked list

void CreatDList(DLIST &DL, int n)
{
    int x;
    Node p = DL;
    p->previous = NULL;
    p->next = new LinkNode;
    p->next->next = NULL;

    for (int i = 0; i < n; i++) {
        cin >> x;
        Insert(x, p);
    }
}

void PrintDList(DLIST DL)
{
    Node p = DL;
    while (p->next != NULL) {
        cout << p->next->data << "\t";
        p = p->next;
    }
    cout << endl;
}

3. The specified value is x The node of is exchanged with its predecessor node

int Swap(Elemtype x, DLIST &DL)
{ // If the element value in the linked list is x The node of , Exchange it with its predecessor node 
    Node p1, p2;
    p1 = Locate(x, DL);
    if (p1 == NULL)
        return 0;
    else {
        Insert(x, p1->previous->previous);
        Delete(p1); // First put the new x Insert the front of the precursor node , Delete the old x
        return 1;
    }
}

int main()
{
    DLIST DL = new LinkNode;
    cout << " Input 5 Create a two-way linked list of data : ";
    CreatDList(DL, 5);
    PrintDList(DL);
    Swap(2, DL);
    PrintDList(DL);
}