insert_linked_list.cpp

#include<iostream>
using namespace std;

class Node{
	public:
		int data;
		Node *next;
	
}*first=NULL;

void create(int a[],int n){
	int i;
	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;
		
	}
}

int count(Node *p){
	int c=0;
	while(p){
		c++;
		p=p->next;
		
	}
	return c;
}


int max(Node *p){
	int m = -32768;
	
	while(p){
		if(p->data>m)
			m = p->data;
		p=p->next;
	}
	return m;
}

void display(Node *p){
	while(p!=NULL){
		cout<<p->data<<" ";
		p=p->next;
		
	}
}

Node * Lsearch(Node *p,int key){
	while(p!=NULL){
		if(key==p->data)
			return p;
		p=p->next;
		
	}
	return NULL;
}

Node * eff_Lsearch(Node *p,int key){
	Node *q=NULL;
	while(p!=NULL){
		if(key==p->data){
			q->next=p->next;
			p->next=first;
			first=p;
			return p;
		}
		q=p;
		p=p->next;
		
	}
	return NULL;
}

Node * Rsearch(Node *p,int key){
	if(p==NULL)
		return NULL;
	if(key==p->data)
		return p;
	return Rsearch(p->next,key);
}

void insert(Node *p, int index,int x){
	Node *t;
	int i;
	if(index<0 || index>count(p))
		return;
	t = new Node();
	t->data = x;
	if(index == 0){
		t->next = first;
		first = t;
		
	}
	else{
		for(i=0;i<index-1;i++)
			p=p->next;
		
		t->next = p->next;
		p->next = t;
		
	}
}
int main(){
	Node *temp;
//	int a[] = {8,18,28};
//	create(a,3);
	insert(first,0,4);
	insert(first,1,8);
	insert(first,2,18);
	insert(first,3,28);
//	rec_display(first);
//	cout<<"Count: "<<count(first);
//	cout<<"Recursive Count: "<<rec_count(first);
//	cout<<"Sum is: "<<add(first);
//	cout<<"Maximum: "<<max(first);
//	temp = Lsearch(first,18);
//	temp = eff_Lsearch(first,18);
//	if(temp)
//		cout<<"Key found :"<<temp->data<<"\n";
//	else
//		cout<<"Key not found"<<"\n";
	display(first);
	
	return 0;
}