#include <iostream>
using namespace std;

class Node{
  public:
  char data;
  Node* next;
  Node(char val){
    data=val;
    next=NULL;
  }
};

int count[1000];

class LL{
  public:
  Node* head;
  Node* last;
  LL(){
    head=NULL;
    last=NULL;
  }
  void insert(Node *newNode){
    if(head==NULL){
    head=last=newNode;
    return;
    }
    last->next=newNode;
    last=newNode;
  }
  void insertatPos(Node *newNode,int pos){
    int count=1;
    Node *temp=head;
    while(1){
      if(count==pos-1)
      break;
      count++;
      temp=temp->next;
    }
    newNode->next=temp->next;
    temp->next=newNode;
  }
  void del(int pos){
    Node *first=head,*second=head;
    while(pos--){
      first=first->next;
    }
    while(first!=NULL){
      first=first->next;
      second=second->next;
    }
    second->data=second->next->data;
    second->next=second->next->next;
  }
  void print(){
    if(size()==0){
      cout<<"Linked List is empty!";
      return;
    }
    Node *temp=head;
    while(temp!=NULL){
      cout<<temp->data<<" ";
      temp=temp->next;
    }
    delete temp;
  }
  int size(){
    int count=0;
    Node *temp=head;
    while(temp!=NULL){
      count++;
      temp=temp->next;
    }
    delete temp;
    return count;
  }
  int* LL_to_array(){
    Node *temp=head;
    int k=0;
    int *a=new int[size()];
    while(temp!=NULL){
      a[k++]=temp->data;
      temp=temp->next;
    }
    return a;
  }
  void detect_duplicate(){
    Node *temp=head;
    while(temp!=NULL){
      count[temp->data]++;
      temp=temp->next;
    }
    cout<<"Duplicate nodes are : ";
    for(int i=0;i<1000;i++){
      if(count[i]>1)
      cout<<i<<" ";
    }
  }
void rearrange ()
{
 Node *p, *q;
 char temp;
 if(!head || !head -> next ) return;
 p = head; q = head -> next;
 while (q) {
 temp = p -> data;
 p -> data = q -> data;
 q -> data = temp;
 p = q -> next;
 q = p ? p -> next : 0;
 }
 }

};

int main() 
{
  char data;
  LL list;
    while(cin>>data){
      Node *newNode=new Node(data);
      list.insert(newNode);
    }
    list.rearrange();
    
    cout<<endl;
    list.print();
    //list.detect_duplicate();
    return 0;
}
by

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Read inputs from stdin

OneCompiler's C++ online compiler supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample program which takes name as input and print your name with hello.

#include <iostream>
#include <string>
using namespace std;

int main() 
{
    string name;
    cout << "Enter name:";
    getline (cin, name);
    cout << "Hello " << name;
    return 0;
}

About C++

C++ is a widely used middle-level programming language.

  • Supports different platforms like Windows, various Linux flavours, MacOS etc
  • C++ supports OOPS concepts like Inheritance, Polymorphism, Encapsulation and Abstraction.
  • Case-sensitive
  • C++ is a compiler based language
  • C++ supports structured programming language
  • C++ provides alot of inbuilt functions and also supports dynamic memory allocation.
  • Like C, C++ also allows you to play with memory using Pointers.

Syntax help

Loops

1. If-Else:

When ever you want to perform a set of operations based on a condition If-Else is used.

if(conditional-expression) {
   //code
}
else {
   //code
}

You can also use if-else for nested Ifs and If-Else-If ladder when multiple conditions are to be performed on a single variable.

2. Switch:

Switch is an alternative to If-Else-If ladder.

switch(conditional-expression){    
case value1:    
 // code    
 break;  // optional  
case value2:    
 // code    
 break;  // optional  
......    
    
default:     
 code to be executed when all the above cases are not matched;    
}

3. For:

For loop is used to iterate a set of statements based on a condition.

for(Initialization; Condition; Increment/decrement){  
  //code  
}

4. While:

While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.

while (condition) {  
// code 
}

5. Do-While:

Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.

do {  
 // code 
} while (condition);

Functions

Function is a sub-routine which contains set of statements. Usually functions are written when multiple calls are required to same set of statements which increases re-usuability and modularity. Function gets run only when it is called.

How to declare a Function:

return_type function_name(parameters);

How to call a Function:

function_name (parameters)

How to define a Function:

return_type function_name(parameters) {  
 // code
}