![Using the Coin Class
The Coin class from Listing 5.4 in the text is in the file Coin.java. Copy it to your directory, then
write a program to find the length of the longest run of heads in 100 flips of the coin. A skeleton
of the program is in the file Runs.java. To use the Coin class you need to do the following in the
program:
1. Create a coin object. 2. Inside the loop, you should use the flip method to flip the coin, the
toString method (used implicitly) to print the results of the flip, and the getFace method to see if
the result was HEADS. Keeping track of the current run length (the number of times in a row
that the coin was HEADS) and the maximum run length is an exercise in loop techniques! 3.
Print the result after the loop.
// ******************************************************************* //
Coin.java Author: Lewis and Loftus // // Represents a coin with two sides that can be flipped. //
*******************************************************************
public class Coin { public final int HEADS = 0; public final int TAILS = 1;
private int face;
// --------------------------------------------- // Sets up the coin by flipping it initially. // ----------------
----------------------------- public Coin () { flip(); }
// ----------------------------------------------- // Flips the coin by randomly choosing a face. // --------
--------------------------------------- public void flip() { face = (int) (Math.random() * 2); }
// ----------------------------------------------------- // Returns the current face of the coin as an
integer. // ----------------------------------------------------- public int getFace() { return face; }
// ---------------------------------------------------- // Returns the current face of the coin as a string. //
---------------------------------------------------- public String toString() { String faceName;
if (face == HEADS) faceName = "Heads";
Chapter 5: Conditionals and Loops 87
else faceName = "Tails";
return faceName; } }
// ******************************************************************** //
Runs.java // // Finds the length of the longest run of heads in 100 flips of a coin. //
********************************************************************
import java.util.Scanner;
public class Runs { public static void main (String[] args) { final int FLIPS = 100; // number of
coin flips
int currentRun = 0; // length of the current run of HEADS int maxRun = 0; // length of the
maximum run so far](https://image.slidesharecdn.com/usingthecoinclassthecoinclassfromlisting5-230403170721-2776c80e/85/Using-the-Coin-Class-The-Coin-class-from-Listing-5-4-in-the-text-i-pdf-1-320.jpg)
![{
String faceName;
if (face == HEADS)
faceName = "Heads";
else
faceName = "Tails";
return faceName;
}
}
// ********************************************************************
// Runs.java
// Finds the length of the longest run of heads in 100 flips of a coin.
// ********************************************************************
import java.util.Scanner;
public class Runs
{
public static void main (String[] args)
{
final int FLIPS = 100; // number of coin flips
int currentRun = 0; // length of the current run of HEADS
int maxRun = 0; // length of the maximum run so far
Scanner scan = new Scanner(System.in);
// Create a coin object
Coin c = new Coin();
int face;
// Flip the coin FLIPS times
for (int i = 0; i < FLIPS; i++)
{
// Flip the coin & print the result
c.flip();
face = c.getFace();
System.out.println("Flip " + (i+1) +": " + c.toString());
if(face == 0)](https://image.slidesharecdn.com/usingthecoinclassthecoinclassfromlisting5-230403170721-2776c80e/85/Using-the-Coin-Class-The-Coin-class-from-Listing-5-4-in-the-text-i-pdf-3-320.jpg)
Using the Coin Class The Coin class from Listing 5.4 in the text i.pdf
- 1. Using the Coin Class The Coin class from Listing 5.4 in the text is in the file Coin.java. Copy it to your directory, then write a program to find the length of the longest run of heads in 100 flips of the coin. A skeleton of the program is in the file Runs.java. To use the Coin class you need to do the following in the program: 1. Create a coin object. 2. Inside the loop, you should use the flip method to flip the coin, the toString method (used implicitly) to print the results of the flip, and the getFace method to see if the result was HEADS. Keeping track of the current run length (the number of times in a row that the coin was HEADS) and the maximum run length is an exercise in loop techniques! 3. Print the result after the loop. // ******************************************************************* // Coin.java Author: Lewis and Loftus // // Represents a coin with two sides that can be flipped. // ******************************************************************* public class Coin { public final int HEADS = 0; public final int TAILS = 1; private int face; // --------------------------------------------- // Sets up the coin by flipping it initially. // ---------------- ----------------------------- public Coin () { flip(); } // ----------------------------------------------- // Flips the coin by randomly choosing a face. // -------- --------------------------------------- public void flip() { face = (int) (Math.random() * 2); } // ----------------------------------------------------- // Returns the current face of the coin as an integer. // ----------------------------------------------------- public int getFace() { return face; } // ---------------------------------------------------- // Returns the current face of the coin as a string. // ---------------------------------------------------- public String toString() { String faceName; if (face == HEADS) faceName = "Heads"; Chapter 5: Conditionals and Loops 87 else faceName = "Tails"; return faceName; } } // ******************************************************************** // Runs.java // // Finds the length of the longest run of heads in 100 flips of a coin. // ******************************************************************** import java.util.Scanner; public class Runs { public static void main (String[] args) { final int FLIPS = 100; // number of coin flips int currentRun = 0; // length of the current run of HEADS int maxRun = 0; // length of the maximum run so far
- 2. Scanner scan = new Scanner(System.in); // Create a coin object // Flip the coin FLIPS times for (int i = 0; i < FLIPS; i++) { // Flip the coin & print the result // Update the run information } // Print the results } } Solution // ******************************************************************* // Coin.java // Represents a coin with two sides that can be flipped. // ******************************************************************* public class Coin { public final int HEADS = 0; public final int TAILS = 1; private int face; // --------------------------------------------- // Sets up the coin by flipping it initially. // --------------------------------------------- public Coin () { flip(); } // ----------------------------------------------- // Flips the coin by randomly choosing a face. // ----------------------------------------------- public void flip() { face = (int) (Math.random() * 2); } // ----------------------------------------------------- // Returns the current face of the coin as an integer. // ----------------------------------------------------- public int getFace() { return face; } // ---------------------------------------------------- // Returns the current face of the coin as a string. // ---------------------------------------------------- public String toString()
- 3. { String faceName; if (face == HEADS) faceName = "Heads"; else faceName = "Tails"; return faceName; } } // ******************************************************************** // Runs.java // Finds the length of the longest run of heads in 100 flips of a coin. // ******************************************************************** import java.util.Scanner; public class Runs { public static void main (String[] args) { final int FLIPS = 100; // number of coin flips int currentRun = 0; // length of the current run of HEADS int maxRun = 0; // length of the maximum run so far Scanner scan = new Scanner(System.in); // Create a coin object Coin c = new Coin(); int face; // Flip the coin FLIPS times for (int i = 0; i < FLIPS; i++) { // Flip the coin & print the result c.flip(); face = c.getFace(); System.out.println("Flip " + (i+1) +": " + c.toString()); if(face == 0)
- 4. currentRun++; else { // Update the run information if(currentRun > maxRun) maxRun = currentRun; currentRun = 0; } } // Print the results System.out.println("Maximum run of heads in a row: " + maxRun); } } /* OUTPUT: Flip 1: Heads Flip 2: Heads Flip 3: Heads Flip 4: Heads Flip 5: Tails Flip 6: Heads Flip 7: Tails Flip 8: Heads Flip 9: Heads Flip 10: Heads Flip 11: Tails Flip 12: Tails Flip 13: Heads Flip 14: Tails Flip 15: Heads Flip 16: Heads
- 5. Flip 17: Tails Flip 18: Tails Flip 19: Heads Flip 20: Heads Flip 21: Heads Flip 22: Tails Flip 23: Tails Flip 24: Heads Flip 25: Tails Flip 26: Tails Flip 27: Heads Flip 28: Tails Flip 29: Tails Flip 30: Tails Flip 31: Heads Flip 32: Tails Flip 33: Tails Flip 34: Heads Flip 35: Tails Flip 36: Heads Flip 37: Heads Flip 38: Heads Flip 39: Tails Flip 40: Heads Flip 41: Tails Flip 42: Heads Flip 43: Tails Flip 44: Tails Flip 45: Heads Flip 46: Tails Flip 47: Heads Flip 48: Heads Flip 49: Heads Flip 50: Tails Flip 51: Tails Flip 52: Heads
- 6. Flip 53: Heads Flip 54: Heads Flip 55: Tails Flip 56: Heads Flip 57: Tails Flip 58: Heads Flip 59: Heads Flip 60: Heads Flip 61: Heads Flip 62: Heads Flip 63: Tails Flip 64: Heads Flip 65: Heads Flip 66: Tails Flip 67: Heads Flip 68: Tails Flip 69: Heads Flip 70: Heads Flip 71: Tails Flip 72: Heads Flip 73: Heads Flip 74: Heads Flip 75: Tails Flip 76: Tails Flip 77: Tails Flip 78: Heads Flip 79: Heads Flip 80: Heads Flip 81: Tails Flip 82: Heads Flip 83: Heads Flip 84: Tails Flip 85: Heads Flip 86: Heads Flip 87: Heads Flip 88: Heads
- 7. Flip 89: Heads Flip 90: Tails Flip 91: Heads Flip 92: Tails Flip 93: Tails Flip 94: Heads Flip 95: Tails Flip 96: Tails Flip 97: Heads Flip 98: Tails Flip 99: Tails Flip 100: Heads Maximum run of heads in a row: 5 */