/*
Algorithm:
Step 1: Get radius of the cylinder from the user and store in variable r
Step 2: Get height of the cylinder from the user and store in variable h
Step 3: Multiply radius * radius * height * pi and store in v
Step 4: Display the volume
*/

#include <iostream>
using namespace std;


int main()
{
        float r; //define variable for radius
        float h; //define variable for height
        float v;
        float pi;
        pi=3.1416;

        cout<<"Enter radius:";
        cin>>r;

        cout<<"Enter height:";
        cin>>h;

        v=r*r*h*pi;  //compute volume

        cout<<"Radius:"<<r<<"\tHeight:"<<h<<endl; //display radius and height

        cout<<"\n************************\n";

        cout<<"Volume:"<<v<<endl;//display volume

        return 0;
}

//From https://create.arduino.cc/projecthub/abhilashpatel121/easyfft-fast-fourier-transform-fft-for-arduino-9d2677
#include <cmath>
#include <iostream>
const unsigned char sine_data[] = {	//Quarter a sine wave
	0, 
	4, 9, 13, 18, 22, 27, 31, 35, 40, 44, 
	49, 53, 57, 62, 66, 70, 75, 79, 83, 87, 
	91, 96, 100, 104, 108, 112, 116, 120, 124, 127, 
	131, 135, 139, 143, 146, 150, 153, 157, 160, 164, 
	167, 171, 174, 177, 180, 183, 186, 189, 192, 195, //Paste this at top of program
	198, 201, 204, 206, 209, 211, 214, 216, 219, 221, 
	223, 225, 227, 229, 231, 233, 235, 236, 238, 240, 
	241, 243, 244, 245, 246, 247, 248, 249, 250, 251, 
	252, 253, 253, 254, 254, 254, 255, 255, 255, 255
};
float sine(int i){	//Inefficient sine
	int j=i;
	float out;
	while(j < 0) j = j + 360;
	while(j > 360) j = j - 360;
	if(j > -1 && j < 91) out = sine_data[j];
	else if(j > 90 && j < 181) out = sine_data[180 - j];
	else if(j > 180 && j < 271) out = -sine_data[j - 180];
	else if(j > 270 && j < 361) out = -sine_data[360 - j];
	return (out / 255);
}

float cosine(int i){	//Inefficient cosine
	int j = i;
	float out;
	while(j < 0) j = j + 360;
	while(j > 360) j = j - 360;
	if(j > -1 && j < 91) out = sine_data[90 - j];
	else if(j > 90 && j < 181) out = -sine_data[j - 90];
	else if(j > 180 && j < 271) out = -sine_data[270 - j];
	else if(j > 270 && j < 361) out = sine_data[j - 270];
	return (out / 255);
}

//Example data:

//-----------------------------FFT Function----------------------------------------------//
float* FFT(int in[],unsigned int N,float Frequency){	//Result is highest frequencies in order of loudness. Needs to be deleted.
	/*
	Code to perform FFT on arduino,
	setup:
	paste sine_data [91] at top of program [global variable], paste FFT function at end of program
	Term:
	1. in[] : Data array, 
	2. N : Number of sample (recommended sample size 2,4,8,16,32,64,128...)
	3. Frequency: sampling frequency required as input (Hz)

	If sample size is not in power of 2 it will be clipped to lower side of number. 
	i.e, for 150 number of samples, code will consider first 128 sample, remaining sample will be omitted.
	For Arduino nano, FFT of more than 128 sample not possible due to mamory limitation (64 recomended)
	For higher Number of sample may arise Mamory related issue,
	Code by ABHILASH
	Contact: [email protected] 
	Documentation:https://www.instructables.com/member/abhilash_patel/instructables/
	2/3/2021: change data type of N from float to int for >=256 samples
	*/

	unsigned int sampleRates[13]={1,2,4,8,16,32,64,128,256,512,1024,2048};
	int a = N;
	int o;
	for(int i=0;i<12;i++){		//Snapping N to a sample rate in sampleRates
		if(sampleRates[i]<=a){
			o = i;
		}
	}
		 
	int in_ps[sampleRates[o]] = {}; //input for sequencing
	float out_r[sampleRates[o]] = {}; //real part of transform
	float out_im[sampleRates[o]] = {}; //imaginory part of transform
	int x = 0; 
	int c1;
	int f;
	for(int b=0;b<o;b++){ // bit reversal
		c1 = sampleRates[b];
		f = sampleRates[o] / (c1 + c1);
		for(int j = 0;j < c1;j++){ 
			x = x + 1;
			in_ps[x]=in_ps[j]+f;
		}
	}

	
	for(int i=0;i<sampleRates[o];i++){ // update input array as per bit reverse order
		if(in_ps[i]<a){
			out_r[i]=in[in_ps[i]];
		}
		if(in_ps[i]>a){
			out_r[i]=in[in_ps[i]-a];
		} 
	}


	int i10,i11,n1;
	float e,c,s,tr,ti;

	for(int i=0;i<o;i++){ //fft
		i10 = sampleRates[i]; // overall values of sine/cosine :
		i11 = sampleRates[o] / sampleRates[i+1]; // loop with similar sine cosine:
		e = 360 / sampleRates[i+1];
		e = 0 - e;
		n1 = 0;

		for(int j=0;j<i10;j++){
			c=cosine(e*j);
			s=sine(e*j); 
			n1=j;

			for(int k=0;k<i11;k++){
				tr = c*out_r[i10 + n1]-s*out_im[i10 + n1];
				ti = s*out_r[i10 + n1]+c*out_im[i10 + n1];

				out_r[n1 + i10] = out_r[n1]-tr;
				out_r[n1] = out_r[n1]+tr;

				out_im[n1 + i10] = out_im[n1]-ti;
				out_im[n1] = out_im[n1]+ti; 

				n1 = n1+i10+i10;
			} 
		}
	}

	/*
	for(int i=0;i<sampleRates[o];i++)
	{
	std::cout << (out_r[i]);
	std::cout << ("\t"); // un comment to print RAW o/p 
	std::cout << (out_im[i]); std::cout << ("i"); 
	std::cout << std::endl;
	}
	*/


	//---> here onward out_r contains amplitude and our_in conntains frequency (Hz)
	for(int i=0;i<sampleRates[o-1];i++){ // getting amplitude from compex number
		out_r[i] = sqrt(out_r[i]*out_r[i]+out_im[i]*out_im[i]); // to increase the speed delete sqrt
		out_im[i] = i * Frequency / N;
		std::cout << (out_im[i]); std::cout << ("Hz");
		std::cout << ("\t");	// un comment to print freuency bin 
		std::cout << (out_r[i]);
		std::cout << std::endl;
	}




	x = 0; // peak detection
	for(int i=1;i<sampleRates[o-1]-1;i++){
		if(out_r[i]>out_r[i-1] && out_r[i]>out_r[i+1]){
			in_ps[x] = i; //in_ps array used for storage of peak number
			x = x + 1;
		} 
	}


	s = 0;
	c = 0;
	for(int i=0;i<x;i++){ // re arraange as per magnitude
		for(int j=c;j<x;j++){
			if(out_r[in_ps[i]]<out_r[in_ps[j]]){
				s=in_ps[i];
				in_ps[i]=in_ps[j];
				in_ps[j]=s;
			}
		}
		c=c+1;
	}
	float* f_peaks = new float[sampleRates[o]];
	for(int i=0;i<5;i++){ // updating f_peak array (global variable)with descending order
		f_peaks[i]=out_im[in_ps[i]];
	}
	return f_peaks;
}

//------------------------------------------------------------------------------------//
//main.cpp
int data[64]={
14, 30, 35, 34, 34, 40, 46, 45, 30, 4, -26, -48, -55, -49, -37,
-28, -24, -22, -13, 6, 32, 55, 65, 57, 38, 17, 1, -6, -11, -19, -34, 
-51, -61, -56, -35, -7, 18, 32, 35, 34, 35, 41, 46, 43, 26, -2, -31, -50,
-55, -47, -35, -27, -24, -21, -10, 11, 37, 58, 64, 55, 34, 13, -1, -7
};

int main(){
	const unsigned int SAMPLE_RATE = 48*1000;	//48khz
	auto result = FFT(data,64,SAMPLE_RATE);
	std::cout << result[0] << " " << result[1] << " " << result[2] << " " << result[3] << std::endl;
	delete[] result;
	return 0;
}

using namespace std; 
  
class Hash 
{ 
    int BUCKET;    // No. of buckets 
  
    // Pointer to an array containing buckets 
    list<int> *table; 
public: 
    Hash(int V);  // Constructor 
  
    // inserts a key into hash table 
    void insertItem(int x); 
  
    // deletes a key from hash table 
    void deleteItem(int key); 
  
    // hash function to map values to key 
    int hashFunction(int x) { 
        return (x % BUCKET); 
    } 
  
    void displayHash(); 
}; 
  
Hash::Hash(int b) 
{ 
    this->BUCKET = b; 
    table = new list<int>[BUCKET]; 
} 
  
void Hash::insertItem(int key) 
{ 
    int index = hashFunction(key); 
    table[index].push_back(key);  
} 
  
void Hash::deleteItem(int key) 
{ 
  // get the hash index of key 
  int index = hashFunction(key); 
  
  // find the key in (inex)th list 
  list <int> :: iterator i; 
  for (i = table[index].begin(); 
           i != table[index].end(); i++) { 
    if (*i == key) 
      break; 
  } 
  
  // if key is found in hash table, remove it 
  if (i != table[index].end()) 
    table[index].erase(i); 
} 
  
// function to display hash table 
void Hash::displayHash() { 
  for (int i = 0; i < BUCKET; i++) { 
    cout << i; 
    for (auto x : table[i]) 
      cout << " --> " << x; 
    cout << endl; 
  } 
} 
  
// Driver program  
int main() 
{ 
  // array that contains keys to be mapped 
  int a[] = {15, 11, 27, 8, 12}; 
  int n = sizeof(a)/sizeof(a[0]); 
  
  // insert the keys into the hash table 
  Hash h(7);   // 7 is count of buckets in 
               // hash table 
  for (int i = 0; i < n; i++)  
    h.insertItem(a[i]);   
  
  // delete 12 from hash table 
  h.deleteItem(12); 
  
  // display the Hash table 
  h.displayHash(); 
  
  return 0; 
}

#include <iostream>
#include <vector>
#include <utility>
#include <algorithm>
#include <chrono>
using namespace std;

#include <stdio.h>
#include <Windows.h>

int nScreenWidth = 120;			// Console Screen Size X (columns)
int nScreenHeight = 40;			// Console Screen Size Y (rows)
int nMapWidth = 16;				// World Dimensions
int nMapHeight = 16;

float fPlayerX = 14.7f;			// Player Start Position
float fPlayerY = 5.09f;
float fPlayerA = 0.0f;			// Player Start Rotation
float fFOV = 3.14159f / 4.0f;	// Field of View
float fDepth = 16.0f;			// Maximum rendering distance
float fSpeed = 5.0f;			// Walking Speed

int main()
{
	// Create Screen Buffer
	wchar_t *screen = new wchar_t[nScreenWidth*nScreenHeight];
	HANDLE hConsole = CreateConsoleScreenBuffer(GENERIC_READ | GENERIC_WRITE, 0, NULL, CONSOLE_TEXTMODE_BUFFER, NULL);
	SetConsoleActiveScreenBuffer(hConsole);
	DWORD dwBytesWritten = 0;

	// Create Map of world space # = wall block, . = space
	wstring map;
	map += L"#########.......";
	map += L"#...............";
	map += L"#.......########";
	map += L"#..............#";
	map += L"#......##......#";
	map += L"#......##......#";
	map += L"#..............#";
	map += L"###............#";
	map += L"##.............#";
	map += L"#......####..###";
	map += L"#......#.......#";
	map += L"#......#.......#";
	map += L"#..............#";
	map += L"#......#########";
	map += L"#..............#";
	map += L"################";

	auto tp1 = chrono::system_clock::now();
	auto tp2 = chrono::system_clock::now();
	
	while (1)
	{
		// We'll need time differential per frame to calculate modification
		// to movement speeds, to ensure consistant movement, as ray-tracing
		// is non-deterministic
		tp2 = chrono::system_clock::now();
		chrono::duration<float> elapsedTime = tp2 - tp1;
		tp1 = tp2;
		float fElapsedTime = elapsedTime.count();


		// Handle CCW Rotation
		if (GetAsyncKeyState((unsigned short)'A') & 0x8000)
			fPlayerA -= (fSpeed * 0.75f) * fElapsedTime;

		// Handle CW Rotation
		if (GetAsyncKeyState((unsigned short)'D') & 0x8000)
			fPlayerA += (fSpeed * 0.75f) * fElapsedTime;
		
		// Handle Forwards movement & collision
		if (GetAsyncKeyState((unsigned short)'W') & 0x8000)
		{
			fPlayerX += sinf(fPlayerA) * fSpeed * fElapsedTime;;
			fPlayerY += cosf(fPlayerA) * fSpeed * fElapsedTime;;
			if (map.c_str()[(int)fPlayerX * nMapWidth + (int)fPlayerY] == '#')
			{
				fPlayerX -= sinf(fPlayerA) * fSpeed * fElapsedTime;;
				fPlayerY -= cosf(fPlayerA) * fSpeed * fElapsedTime;;
			}			
		}

		// Handle backwards movement & collision
		if (GetAsyncKeyState((unsigned short)'S') & 0x8000)
		{
			fPlayerX -= sinf(fPlayerA) * fSpeed * fElapsedTime;;
			fPlayerY -= cosf(fPlayerA) * fSpeed * fElapsedTime;;
			if (map.c_str()[(int)fPlayerX * nMapWidth + (int)fPlayerY] == '#')
			{
				fPlayerX += sinf(fPlayerA) * fSpeed * fElapsedTime;;
				fPlayerY += cosf(fPlayerA) * fSpeed * fElapsedTime;;
			}
		}

		for (int x = 0; x < nScreenWidth; x++)
		{
			// For each column, calculate the projected ray angle into world space
			float fRayAngle = (fPlayerA - fFOV/2.0f) + ((float)x / (float)nScreenWidth) * fFOV;

			// Find distance to wall
			float fStepSize = 0.1f;		  // Increment size for ray casting, decrease to increase										
			float fDistanceToWall = 0.0f; //                                      resolution

			bool bHitWall = false;		// Set when ray hits wall block
			bool bBoundary = false;		// Set when ray hits boundary between two wall blocks

			float fEyeX = sinf(fRayAngle); // Unit vector for ray in player space
			float fEyeY = cosf(fRayAngle);

			// Incrementally cast ray from player, along ray angle, testing for 
			// intersection with a block
			while (!bHitWall && fDistanceToWall < fDepth)
			{
				fDistanceToWall += fStepSize;
				int nTestX = (int)(fPlayerX + fEyeX * fDistanceToWall);
				int nTestY = (int)(fPlayerY + fEyeY * fDistanceToWall);
				
				// Test if ray is out of bounds
				if (nTestX < 0 || nTestX >= nMapWidth || nTestY < 0 || nTestY >= nMapHeight)
				{
					bHitWall = true;			// Just set distance to maximum depth
					fDistanceToWall = fDepth;
				}
				else
				{
					// Ray is inbounds so test to see if the ray cell is a wall block
					if (map.c_str()[nTestX * nMapWidth + nTestY] == '#')
					{
						// Ray has hit wall
						bHitWall = true;

						// To highlight tile boundaries, cast a ray from each corner
						// of the tile, to the player. The more coincident this ray
						// is to the rendering ray, the closer we are to a tile 
						// boundary, which we'll shade to add detail to the walls
						vector<pair<float, float>> p;

						// Test each corner of hit tile, storing the distance from
						// the player, and the calculated dot product of the two rays
						for (int tx = 0; tx < 2; tx++)
							for (int ty = 0; ty < 2; ty++)
							{
								// Angle of corner to eye
								float vy = (float)nTestY + ty - fPlayerY;
								float vx = (float)nTestX + tx - fPlayerX;
								float d = sqrt(vx*vx + vy*vy); 
								float dot = (fEyeX * vx / d) + (fEyeY * vy / d);
								p.push_back(make_pair(d, dot));
							}

						// Sort Pairs from closest to farthest
						sort(p.begin(), p.end(), [](const pair<float, float> &left, const pair<float, float> &right) {return left.first < right.first; });
						
						// First two/three are closest (we will never see all four)
						float fBound = 0.01;
						if (acos(p.at(0).second) < fBound) bBoundary = true;
						if (acos(p.at(1).second) < fBound) bBoundary = true;
						if (acos(p.at(2).second) < fBound) bBoundary = true;
					}
				}
			}
		
			// Calculate distance to ceiling and floor
			int nCeiling = (float)(nScreenHeight/2.0) - nScreenHeight / ((float)fDistanceToWall);
			int nFloor = nScreenHeight - nCeiling;

			// Shader walls based on distance
			short nShade = ' ';
			if (fDistanceToWall <= fDepth / 4.0f)			nShade = 0x2588;	// Very close	
			else if (fDistanceToWall < fDepth / 3.0f)		nShade = 0x2593;
			else if (fDistanceToWall < fDepth / 2.0f)		nShade = 0x2592;
			else if (fDistanceToWall < fDepth)				nShade = 0x2591;
			else											nShade = ' ';		// Too far away

			if (bBoundary)		nShade = ' '; // Black it out
			
			for (int y = 0; y < nScreenHeight; y++)
			{
				// Each Row
				if(y <= nCeiling)
					screen[y*nScreenWidth + x] = ' ';
				else if(y > nCeiling && y <= nFloor)
					screen[y*nScreenWidth + x] = nShade;
				else // Floor
				{				
					// Shade floor based on distance
					float b = 1.0f - (((float)y -nScreenHeight/2.0f) / ((float)nScreenHeight / 2.0f));
					if (b < 0.25)		nShade = '#';
					else if (b < 0.5)	nShade = 'x';
					else if (b < 0.75)	nShade = '.';
					else if (b < 0.9)	nShade = '-';
					else				nShade = ' ';
					screen[y*nScreenWidth + x] = nShade;
				}
			}
		}

		// Display Stats
		swprintf_s(screen, 40, L"X=%3.2f, Y=%3.2f, A=%3.2f FPS=%3.2f ", fPlayerX, fPlayerY, fPlayerA, 1.0f/fElapsedTime);

		// Display Map
		for (int nx = 0; nx < nMapWidth; nx++)
			for (int ny = 0; ny < nMapWidth; ny++)
			{
				screen[(ny+1)*nScreenWidth + nx] = map[ny * nMapWidth + nx];
			}
		screen[((int)fPlayerX+1) * nScreenWidth + (int)fPlayerY] = 'P';

		// Display Frame
		screen[nScreenWidth * nScreenHeight - 1] = '\0';
		WriteConsoleOutputCharacter(hConsole, screen, nScreenWidth * nScreenHeight, { 0,0 }, &dwBytesWritten);
	}

	return 0;
}

#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;
      }
   }
}

/*
Good morning! Here's your coding interview problem for today.

This problem was asked by LinkedIn.

A wall consists of several rows of bricks of various integer lengths and uniform height. Your goal is to find a vertical line going from the top to the bottom of the wall that cuts through the fewest number of bricks. If the line goes through the edge between two bricks, this does not count as a cut.

For example, suppose the input is as follows, where values in each row represent the lengths of bricks in that row:

[[3, 5, 1, 1],
	[2, 3, 3, 2],
	[5, 5],
	[4, 4, 2],
	[1, 3, 3, 3],
	[1, 1, 6, 1, 1]]

The best we can we do here is to draw a line after the eighth brick, which will only require cutting through the bricks in the third and fifth row.

Given an input consisting of brick lengths for each row such as the one above, return the fewest number of bricks that must be cut to create a vertical line.

AUTHORS NOTE:
Makes following assumptions:
- Each row is same length
- Data is in file called "data.dat" and formatted in space-separated rows
- The cuts at the beginning and end of the wall are not solutions

This requires the following file named data.dat that is a space separated file, or similar formatted file:
----START FILE----
3 5 1 1
2 3 3 2
5 5
4 4 2
1 3 3 3
1 1 6 1 1
----END FILE----
*/

#include <algorithm>
#include <iostream>
#include <fstream>
#include <map>
#include <sstream>
#include <string>
#include <vector>
using namespace std;

int main()
{
	vector<vector<int>> wall;

	ifstream in;
	in.open("data.dat");
	if(!in.good())
	{
	cout << "ERROR: File failed to open properly.\n";
	}

	/* Get input from space separated file */
	string line;
	while(!in.eof())
	{
	getline(in, line);

	int i;
	vector<int> currv;
	stringstream strs(line);
	while(strs >> i)
	currv.push_back(i);
	wall.push_back(currv);
	}

	

	/* Convert each value from "length of brick" to "position at end of brick" */
	for(int y = 0; y < wall.size(); y++)
	{
	wall.at(y).pop_back(); //Delet last val
	for(int x = 1; x < wall.at(y).size(); x++) //Skip the first bc data doesn't need change
	wall.at(y).at(x) += wall.at(y).at(x-1);
	}

	/* Check output. COMMENT OUT */
	// for(auto row : wall)
	// {
	// for(int pos : row)
	// cout << pos << " ";
	// cout << endl;
	// }

	/* Determine which ending position is most common, and cut there */
	//Exclude final position, which will be the size of the wall

	int mode = -1;
	int amt = -1;
	vector<int> tried;
	for(auto row : wall)
	{
	for(int pos : row) //For each pos in the wall
	{
	//Guard. If pos is contained in the list, skip pos
	if(find(tried.begin(), tried.end(), pos) != tried.end())
	continue;
	tried.push_back(pos);

	/* Cycle through each row to see if it contains the pos */
	int curramt = 0;
	for(auto currrow : wall)
	{
	if( find( currrow.begin(), currrow.end(), pos ) != currrow.end() )
	curramt++;
	}
	//cout << pos << " " << curramt << endl; 

	if(curramt > amt)
	{
	amt = curramt;
	mode = pos;
	}
	}
	}

	cout << "Please cut at position " << mode << endl;
	cout << "This will cut through " << (wall.size() - amt) << " bricks." << endl;

	return 0;
}