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Copy pathcpp-data-structures-linked-list-insert.cpp
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cpp-data-structures-linked-list-insert.cpp
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#include <iostream>
using namespace std;
struct Node {
int data; // data member
struct Node* next; // self-referencial member pointer
}
*first = NULL;
void create(int A[], int n) // creating a linked list from an array
{
int i;
struct Node* t, * last;
first = new Node;
first->data = A[0];
first->next = NULL;
last = first;
for (i = 1; i < n; i++)
{
t = new Node;
t->data = A[i];
t->next = NULL;
last->next = t;
last = t;
}
}
struct Node* LSearch(struct Node* p, int key) // linear search for an element and moves it to front position
{
struct Node* q = NULL;
while (p != NULL) {
if (key == p->data)
{
if (p != first)
{
q->next = p->next;
p->next = first;
first = p;
return p;
}
}
q = p;
p = p->next;
}
return NULL;
}
void Display(struct Node* p) // display the linked list elements
{
while (p != NULL)
{
cout << p->data << " " ;
p = p->next;
}
cout << endl;
}
int count(struct Node* p) // count a linked list
{
int count = 0;
while (p)
{
count++;
p = p->next;
}
return count;
}
void Insert(struct Node* p, int index, int key) // insert node at given position
{
struct Node *t;
int i;
if (index < 0 || index > count(p)) // checks the validity of the index
return;
t = new Node; // create new node
t->data = key; // put data in new node
if (index == 0) // put the new node on first position
{
t->next = first;
first = t;
}
else
{
for (i = 0; i < index - 1; i++) // loop through the list with p to find the desired index - 1
p = p->next;
t->next = p->next;
p->next = t;
}
}
void SortedInsert(struct Node * p, int x) {
struct Node *t,*q = NULL;
t = new Node;
t->data = x;
t->next = NULL;
if (first == NULL) // checks if linked list is empty
first = t;
else
{
while (p && p->data < x)
{
q = p;
p = p->next;
}
if (p == first) { // new element will be inserted to first position
t->next = first;
first = t;
}
else
{
t->next = q->next;
q->next = t;
}
}
}
int main() {
int A[] = { 3,5,7,9,11};
create(A, 5);
SortedInsert(first,6);
Display(first);
return 0;
}