#include <iostream>
using namespace std;

int main {
   cout << 1; 
}

#include <iostream>
#include <fstream>
#include <string>
#include <cstring>

using namespace std;

//This program makes a new text file that contains all combinations of two letters.
// aa, ab, ..., zy, zz

int main(){
	string filename = "two_letters.txt";

	ofstream outFile;
	outFile.open(filename.c_str());

	if(!outFile.is_open()){
		cout << "Something's wrong. Closing..." << endl;
		return 0;
	}

	for(char first = 'a'; first <= 'z'; first++){
		for(char second = 'a'; second <= 'z'; second++){
			outFile << first << second << " ";
		}
		outFile << endl;
	}

	return 0;
}

#include <iostream>
using namespace std;

int main() {


    int arr[5];
    
    for(int i = 0; i < 5; i++) {
        arr[i] = i;
    }

    for(int i = 0; i < 5; i++) {
        cout << "Outputting array info at position " << i + 1 << ": " << arr[i] << endl;
    }

    for(int i=0;i<5;i++)
	{		
		for(int j=i+1;j<5;j++)
		{
			if(arr[i]>arr[j])
			{
				int temp=arr[i];
				arr[i]=arr[j];
				arr[j]=temp;
			}
		}
	}

    cout << endl;

    for(int i = 0; i < 5; i++) {
        cout << "Outputting sorted array info at position " << i + 1 << ": " << arr[i] << endl;
    }

    return 0;
}

#include <string>
#include <iostream>
#include "PlaylistNode.h"
using namespace std;

PlaylistNode::PlaylistNode() {
   uniqueID = "none";
   songName = "none";
   artistName = "none";
   songLength = 0;
   nextNodePtr = 0;
}

PlaylistNode::PlaylistNode(string uniqueID_, string songName_, string artistName_, int songLength_) {
   uniqueID = uniqueID_;
   songName = songName_;
   artistName = artistName_;
   songLength = songLength_;
   nextNodePtr = 0;
}

void PlaylistNode::InsertAfter(PlaylistNode* ptr) {
   this->SetNext(ptr->GetNext());
   ptr->SetNext(this);
}

void PlaylistNode::SetNext(PlaylistNode* ptr) {
   nextNodePtr = ptr;
}

string PlaylistNode::GetID() {
   return uniqueID;
}

string PlaylistNode::GetSongName() {
   return songName;
}

string PlaylistNode::GetArtistName() {
   return artistName;
}

int PlaylistNode::GetSongLength() {
   return songLength;
}

PlaylistNode* PlaylistNode::GetNext() {
   return nextNodePtr;
}

void PlaylistNode::PrintPlaylistNode() {
   cout << "Unique ID: " << uniqueID << endl;
   cout << "Song Name: " << songName << endl;
   cout << "Artist Name: " << artistName << endl;
   cout << "Song Length (in seconds): " << songLength << endl;
}

Playlist::Playlist() {
   head = tail = 0;
}

void Playlist::AddSong(string id, string songname, string artistname, int length) {
   PlaylistNode* n = new PlaylistNode(id, songname, artistname, length);
   if (head == 0) {
      head = tail = n;
   }
   else {
      n->InsertAfter(tail);
      tail = n;
   }
}

bool Playlist::RemoveSong(string id) {
   if (head == NULL) {
      cout << "Playlist is empty" << endl;
      return false;
   }
   
   PlaylistNode* curr = head;
   PlaylistNode* prev = NULL;
   while (curr != NULL) {
      if (curr->GetID() == id) {
         break;
      }
      prev = curr;
      curr = curr->GetNext();
   }
   
   if (curr == NULL) {
      cout << "\"" << curr->GetSongName() << "\" is not found" << endl;
      return false;
   }
   else {
      if (prev != NULL) {
         prev ->SetNext(curr->GetNext());
      }
      else {
         head = curr->GetNext();
      }
      if (tail == curr) {
         tail = prev;
      }
      cout << "\"" << curr->GetSongName() << "\" removed." << endl;
      delete curr;
      return true;
   }
}

bool Playlist::ChangePosition(int oldPos, int newPos) {
   if (head == NULL) {
      cout << "Playlist is empty" << endl;
      return false;
   }
   
   PlaylistNode* prev = NULL;
   PlaylistNode* curr = head;
   
   int pos;
   if (head == NULL || head == tail) {
      return false;
   }
   
   for (pos = 1; curr != NULL && pos < oldPos; pos++) {
      prev = curr;
      curr = curr->GetNext();
   }
   if (curr != NULL) {
      string currentSong = curr->GetSongName();
      
      if (prev == NULL) {
         head = curr->GetNext();
      }
      else {
         prev->SetNext(curr->GetNext());
      }
      if (curr == tail) {
         tail = prev;
      }
      
      PlaylistNode* curr1 = curr;
      prev = NULL;
      curr = head;
      for (pos = 1; curr != NULL && pos < newPos; pos++) {
         prev = curr;
         curr = curr->GetNext();
      }
      if (prev == NULL) {
         curr1->SetNext(head);
         head = curr1;
      }
      else {
         curr1->InsertAfter(prev);
      }
      if (curr == NULL) {
         tail = curr1;
      }
      cout << "\"" << currentSong << "\" moved to position " << newPos << endl;
      return true;
   }
   else {
      cout << "Song's current position is invalid" << endl;
      return false;
   }
}

void Playlist::SongsByArtist(string artist) {
   if (head == NULL) {
      cout << "Playlist is empty" << endl;
   }
   else {
      PlaylistNode* curr = head;
      int i = 1;
      while (curr != NULL) {
         if (curr->GetArtistName() == artist) {
            cout << endl << i << "." << endl;
            curr->PrintPlaylistNode();
         }
         curr = curr->GetNext();
         i++;
      }
   }
}

int Playlist::TotalTime() {
   int total = 0;
   PlaylistNode* curr = head;
   
   while (curr != NULL) {
      total += curr->GetSongLength();
      curr = curr->GetNext();
   }
   return total;
}

void Playlist::PrintList() {
   if (head == NULL) {
      cout << "Playlist is empty" << endl;
   }
   else {
      PlaylistNode* curr = head;
      int i = 1;
      while (curr != NULL) {
         cout << endl << i++ << "." << endl;
         curr->PrintPlaylistNode();
         curr = curr->GetNext();
      }
   }
}

#include <iostream>
#include "PlaylistNode.h"
using namespace std;
void PrintMenu(string title);

int main() {
   string plTitle;
   cout << "Enter playlist's title:" << endl;
   getline(cin, plTitle);
   PrintMenu(plTitle);
   return 0;
}

void PrintMenu(string title) {
   Playlist list;
   string id;
   string sname;
   string aname;
   int length;
   int oldPos;
   int newPos;
   char choice;
   
   while(true) {
      cout << endl << title << " PLAYLIST MENU" << endl;
      cout << "a - Add song" << endl;
      cout << "d - Remove song" << endl;
      cout << "c - Change position of song" << endl;
      cout << "s - Output songs by specific artist" << endl;
      cout << "t - Output total time of playlist (in seconds)" << endl;
      cout << "o - Output full playlist" << endl;
      cout << "q - Quit" << endl << endl;
      
      cout << "Choose an option:" << endl;
      cin >> choice;
      cin.ignore();
      
      if (choice == 'q') {
         exit(1);
      }
      else if (choice == 'a') {
         cout << "\nADD SONG" << endl;
         cout << "Enter song's unique ID: ";
         cin >> id;
         cin.ignore();
         cout << "Enter song's name: ";
         getline(cin,sname);
         cout << "Enter artist's name: ";
         getline(cin,aname);
         cout << "Enter song's length (in seconds): ";
         cin >> length;
         list.AddSong(id, sname, aname, length);
      }
      else if (choice == 'd') {
         cout << "\nREMOVE SONG" << endl;
         cout << "Enter song's unique ID: ";
         cin >> id;
         list.RemoveSong(id);
      }
      else if (choice == 'c') {
         cout << "\nCHANGE POSITION OF SONG" << endl;
         cout << "Enter song's current position: ";
         cin >> oldPos;
         cout << "Enter new position for song: ";
         cin >> newPos;
         list.ChangePosition(oldPos, newPos);
      }
      else if (choice == 's') {
         cout << "\nOUTPUT SONGS BY SPECIFIC ARTIST" << endl;
         cout << "Enter artist's name: ";
         getline(cin, aname);
         list.SongsByArtist(aname);
      }
      else if (choice == 't') {
         cout << "\nOUTPUT TOTAL TIME OF PLAYLIST (IN SECONDS)" << endl;
         cout << "Total time: " << list.TotalTime() << " seconds" << endl;
      }
      else if (choice == 'o') {
         cout << endl << title << " - OUTPUT FULL PLAYLIST" << endl;
         list.PrintList();
      }
      else {
         cout << "Invalid menu choice! Please try again." << endl;
      }
   }
}

#include <iostream>
using namespace std;

int main()
{
    cout << "Hello, World!" << endl;
    return 0;
}