Untitled

///////////////////////////////////////////////////////////////////
#include<iostream>
using namespace std;
struct node{
  int data;
  node*next;
};
node*head=0,*temp,*newnode;

void displaylist(){
if(head==0){
  cout<<"No data.No list"<<endl;
}
else{
  temp=head;
  cout<<"list is: ";
  while(temp!=0){
    cout<<temp->data<<"->";
    temp=temp->next;
  }
  cout<<"NULL";
  cout<<endl;
}
}

void reverselist(){
node*prevnode,*currentnode,*nextnode;
prevnode=0;
currentnode=nextnode=head;
while(nextnode!=0){
nextnode=nextnode->next;
currentnode->next=prevnode;
prevnode=currentnode;
currentnode=nextnode;
}
head=prevnode;
displaylist();
}

void createlist(){
  int choice=1;
  while(choice){
newnode=new node;
cout<<"enter data: ";
cin>>newnode->data;
newnode->next=0;
if(head==0){
  head=temp=newnode;
}
else{
  temp->next=newnode;
  temp=newnode;
}
  cout<<"do you want to continue(0/1): ";
  cin>>choice;
  }
displaylist();


}
void insertnodeatbeg(){
newnode=new node;
cout<<"enter data: ";
cin>>newnode->data;
newnode->next=head;
head=newnode;
displaylist();
}

void insertnodeatend(){
  newnode=new node;
  cout<<"enter data: ";
  cin>>newnode->data;
  temp=head;
  while(temp->next!=0){
temp=temp->next;
  }
 temp->next=newnode;
newnode->next=0;
temp=newnode;
displaylist();

}
void insertnodeatpos(){
int pos,i=1;
cout<<"enter position: ";
cin>>pos;
if(pos==1){
  insertnodeatbeg();
}
else{
  newnode=new node;
  cout<<"enter data: ";
  cin>>newnode->data;
  temp=head;
  while(i<pos-1){
    temp=temp->next;
    i++;
  }
  newnode->next=temp->next;
  temp->next=newnode;
  
  displaylist();
  
}
}
void deletenodefrombeg(){
temp=head;
head=temp->next;
free(temp);
displaylist();

}

void deletenodefromend(){
  node*prevnode;
temp=head;
while(temp->next!=0){
  prevnode=temp;
  temp=temp->next;
}
if(temp==head){
head=0;
}
else{
  prevnode->next=0;
}
free(temp);
displaylist();
}

void deletenodefrompos(){
int pos;
cout<<"enter position: ";
cin>>pos;
if(pos==1){
  deletenodefrombeg();
}
else{
  node*nextnode;
  int i=1;
  temp=head;
  while(i<pos-1){
   temp=temp->next;
   i++;
  }
  nextnode=temp->next;
  temp->next=nextnode->next;
  free(nextnode);
  displaylist();
  
}
}
void lengthoflist(){
temp=head;
int count=0;
while(temp!=0){
  temp=temp->next;
  count++;
}
cout<<"length of list: "<<count<<endl;
}
int main(){
int choic=1;
while(1){
cout<<endl<<"\tMENU"<<endl;
cout<<"1.Create singly linked list"<<endl;
cout<<"2.Insert data at beginning"<<endl;
cout<<"3.Insert data at end"<<endl;
cout<<"4.Insert data at position"<<endl;
cout<<"5.Delete data from beginning"<<endl;
cout<<"6.Delete data from end"<<endl;
cout<<"7.Delete data from position"<<endl;
cout<<"8.length of list"<<endl;
cout<<"9.Reverse list "<<endl;
cout<<"10.Exit"<<endl;
cout<<endl<<"enter your choice: ";
cin>>choic;
if(choic==10){
  cout<<"exiting of program"<<endl;
  break;
}
else{
  switch(choic){
    case 1: createlist();
    break;
    case 2: insertnodeatbeg();
    break;
    case 3: insertnodeatend();
    break;
    case 4: insertnodeatpos();
    break;
    case 5: deletenodefrombeg();
    break;
    case 6: deletenodefromend();
    break;
    case 7: deletenodefrompos();
    break;
    case 8: lengthoflist();
    break;
    case 9: reverselist();
    break;
    default:cout<<"Invalid choice"<<endl;
  }
}
}
return 0;
}////////////////////////////////////////////////////////////////////////