Write a program called PlaySimpleChords to play a sequence of chords represented as notes in text.

Write the program so that it:

Declares and creates a symbol table using the algs31.BinarySearchST class;

Reads in a file notes_frequencies.txt where each line is a pair of strings separated by whitespace. The first string is the name of a musical note and the second a double value that is its sound frequency as found on a piano. For example, the note A4 is paired with the frequency 440 and the note C4 with the frequency 261.626. As each line is read, an entry is made in the symbol table where the note name is the key and the frequency is the value.

Reads in a chord file, where each line contains two note names and a duration in seconds, separated by whitespace. A sample file is sample_simple_chords.txt, which plays a set of C chords for half a second.

Both the notes and frequencies file and the chord file should be placed into the Eclipse data directory and, as in the previous program, read in using StdIn and the fromFile method.

To process a text file where each line contains a fixed set of data fields:

Use the method readLine in the StdIn class, which returns a string;

Split the string into an array of strings using the instance method split in the String class;

Convert the numeric strings into numeric values using the method parseDouble in the Double class.

To play each chord, place into your program and call this method:

 public static void playChord(double duration, double... frequencies) { final int sliceCount = (int) (StdAudio.SAMPLE_RATE * duration); final double[] slices = new double[sliceCount+1]; for (int i = 0; i <= sliceCount; i++) { for (double frequency: frequencies) { slices[i] += Math.sin(2 * Math.PI * i * frequency / StdAudio.SAMPLE_RATE); } slices[i] /= frequencies.length; } StdAudio.play(slices); } 

For example, if your two frequency variables are frequency1 and frequency2, you can call the above method with the line playChord(duration, frequency1, frequency2);.

You will also have to import stdlib.StdAudio.

sample_simple_chords

C1 C2 0.5 C2 C3 0.5 C3 C4 0.5 C4 C5 0.5 C5 C6 0.5 C6 C7 0.5 C7 C8 0.5

notes_frequencies

A0 27.5

A#0 29.1353

B0 30.8677

C1 32.7032

C#1 34.6479

D1 36.7081

D#1 38.8909

E1 41.2035

F1 43.6536

F#1 46.2493

G1 48.9995

G#1 51.913

A1 55

A#1 58.2705

B1 61.7354

C2 65.4064

C#2 69.2957

D2 73.4162

D#2 77.7817

E2 82.4069

F2 87.3071

F#2 92.4986

G2 97.9989

G#2 103.826

A2 110

A#2 116.541

B2 123.471

C3 130.813

C#3 138.591

D3 146.832

D#3 155.563

E3 164.814

F3 174.614

F#3 184.997

G3 195.998

G#3 207.652

A3 220

A#3 233.082

B3 246.942

C4 261.626

C#4 277.183

D4 293.665

D#4 311.127

E4 329.628

F4 349.228

F#4 369.994

G4 391.995

G#4 415.305

A4 440

A#4 466.164

B4 493.883

C5 523.251

C#5 554.365

D5 587.33

D#5 622.254

E5 659.255

F5 698.456

F#5 739.989

G5 783.991

G#5 830.609

A5 880

A#5 932.328

B5 987.767

C6 1046.5

C#6 1108.73

D6 1174.66

D#6 1244.51

E6 1318.51

F6 1396.91

F#6 1479.98

G6 1567.98

G#6 1661.22

A6 1760

A#6 1864.66

B6 1975.53

C7 2093

C#7 2217.46

D7 2349.32

D#7 2489.02

E7 2637.02

F7 2793.83

F#7 2959.96

G7 3135.96

G#7 3322.44

A7 3520

A#7 3729.31

B7 3951.07

C8 4186.01

// Exercise 3.1.16 3.1.17 3.1.30 (Solution published at http://algs4.cs.princeton.edu/)

package algs31;

import stdlib.*;

import algs13.Queue;

/* ***********************************************************************

* Compilation: javac BinarySearchST.java

* Execution: java BinarySearchST

* Dependencies: StdIn.java StdOut.java

* Data files: http://algs4.cs.princeton.edu/31elementary/tinyST.txt

*

* Symbol table implementation with binary search in an ordered array.

*

* % more tinyST.txt

* S E A R C H E X A M P L E

*

* % java BinarySearchST < tinyST.txt

* A 8

* C 4

* E 12

* H 5

* L 11

* M 9

* P 10

* R 3

* S 0

* X 7

*

*************************************************************************/

public class BinarySearchST, V> {

private static final int INIT_CAPACITY = 2;

private K[] keys;

private V[] vals;

private int N = 0;

// create an empty symbol table with default initial capacity

public BinarySearchST() { this(INIT_CAPACITY); }

// create an empty symbol table with given initial capacity

@SuppressWarnings("unchecked")

public BinarySearchST(int capacity) {

keys = (K[]) new Comparable[capacity];

vals = (V[]) new Object[capacity];

}

// resize the underlying arrays

@SuppressWarnings("unchecked")

private void resize(int capacity) {

if (capacity <= N) throw new IllegalArgumentException ();

K[] tempk = (K[]) new Comparable[capacity];

V[] tempv = (V[]) new Object[capacity];

for (int i = 0; i < N; i++) {

tempk[i] = keys[i];

tempv[i] = vals[i];

}

vals = tempv;

keys = tempk;

}

// is the key in the table?

public boolean contains(K key) { return get(key) != null; }

// number of key-value pairs in the table

public int size() { return N; }

// is the symbol table empty?

public boolean isEmpty() { return size() == 0; }

// return the value associated with the given key, or null if no such key

public V get(K key) {

if (isEmpty()) return null;

int i = rank(key);

if (i < N && keys[i].compareTo(key) == 0) return vals[i];

return null;

}

// return the number of keys in the table that are smaller than given key

public int rank(K key) {

int lo = 0, hi = N-1;

while (lo <= hi) {

int m = lo + (hi - lo) / 2;

int cmp = key.compareTo(keys[m]);

if (cmp < 0) hi = m - 1;

else if (cmp > 0) lo = m + 1;

else return m;

}

return lo;

}

// Search for key. Update value if found; grow table if new.

public void put(K key, V val) {

if (val == null) { delete(key); return; }

int i = rank(key);

// key is already in table

if (i < N && keys[i].compareTo(key) == 0) {

vals[i] = val;

return;

}

// insert new key-value pair

if (N == keys.length) resize(2*keys.length);

for (int j = N; j > i; j--) {

keys[j] = keys[j-1];

vals[j] = vals[j-1];

}

keys[i] = key;

vals[i] = val;

N++;

//assert check();

}

// Remove the key-value pair if present

public void delete(K key) {

if (isEmpty()) return;

// compute rank

int i = rank(key);

// key not in table

if (i == N || keys[i].compareTo(key) != 0) {

return;

}

for (int j = i; j < N-1; j++) {

keys[j] = keys[j+1];

vals[j] = vals[j+1];

}

N--;

keys[N] = null; // to avoid loitering

vals[N] = null;

// resize if 1/4 full

if (N > 0 && N == keys.length/4) resize(keys.length/2);

//assert check();

}

// delete the minimum key and its associated value

public void deleteMin() {

if (isEmpty()) throw new Error("Symbol table underflow error");

delete(min());

}

// delete the maximum key and its associated value

public void deleteMax() {

if (isEmpty()) throw new Error("Symbol table underflow error");

delete(max());

}

/* ***************************************************************************

* Ordered symbol table methods

*****************************************************************************/

public K min() {

if (isEmpty()) return null;

return keys[0];

}

public K max() {

if (isEmpty()) return null;

return keys[N-1];

}

public K select(int k) {

if (k < 0 || k >= N) return null;

return keys[k];

}

public K floor(K key) {

int i = rank(key);

if (i < N && key.compareTo(keys[i]) == 0) return keys[i];

if (i == 0) return null;

else return keys[i-1];

}

public K ceiling(K key) {

int i = rank(key);

if (i == N) return null;

else return keys[i];

}

public int size(K lo, K hi) {

if (lo.compareTo(hi) > 0) return 0;

if (contains(hi)) return rank(hi) - rank(lo) + 1;

else return rank(hi) - rank(lo);

}

public Iterable keys() {

return keys(min(), max());

}

public Iterable keys(K lo, K hi) {

Queue queue = new Queue<>();

if (lo == null && hi == null) return queue;

if (lo == null) throw new Error("lo is null in keys()");

if (hi == null) throw new Error("hi is null in keys()");

if (lo.compareTo(hi) > 0) return queue;

for (int i = rank(lo); i < rank(hi); i++)

queue.enqueue(keys[i]);

if (contains(hi)) queue.enqueue(keys[rank(hi)]);

return queue;

}

/* ***************************************************************************

* Check internal invariants

*****************************************************************************/

private boolean check() {

return isSorted() && rankCheck();

}

// are the items in the array in ascending order?

private boolean isSorted() {

for (int i = 1; i < size(); i++)

if (keys[i].compareTo(keys[i-1]) < 0) return false;

return true;

}

// check that rank(select(i)) = i

private boolean rankCheck() {

for (int i = 0; i < size(); i++)

if (i != rank(select(i))) return false;

for (int i = 0; i < size(); i++)

if (keys[i].compareTo(select(rank(keys[i]))) != 0) return false;

return true;

}

/* ***************************************************************************

* Test client

*****************************************************************************/

public static void main(String[] args) {

StdIn.fromFile("data/tiny.txt");

BinarySearchST st = new BinarySearchST<>();

for (int i = 0; !StdIn.isEmpty(); i++) {

String key = StdIn.readString();

st.put(key, i);

}

for (String s : st.keys())

StdOut.println(s + " " + st.get(s));

}

}