Java Help

I'm trying to complete a project and i'm getting an error message at the end where it says public static int factorial (int n). Does anyone know what I'm doing wrong?


import java.util.Scanner;

public class Histogram {

private static final int MIN_HEADS = 0; // minimum number of heads per set

/**
* main method:
* ask the user how many sets of coin flips and how many flips per set
* count occurances of heads in user specified number of sets of coin flips
* draw a horizontal and vertical histogram of the number of heads
*/
public static void main(String[] args) {

// set up to get user input
Scanner scan = new Scanner(System.in);

// ask user for the number of sets of coin flips
System.out.println("How many sets of coin flips do you want?");
int nSets = scan.nextInt();

// ask user for the number of coin flips per set
System.out.println("How many coin flips per set do you want?");
int nFlips = scan.nextInt();

// maximum number of heads that can occur is number of flips
int maxHeads = nFlips;

// calculate maximum length of histogram bars based on number of flips per set
// based on finding the number of combinations for half heads / half tails
// n!
// formula is ----------- with r = n/2
// r! (n-r)!

int maxLength = factorial (nFlips) /
(factorial (nFlips / 2) * factorial (nFlips - nFlips / 2));

// instantiate a coin object named myCoin
Coin myCoin = new Coin();

// step 1:
// declare an int array named "counts" to count coin flip occurences
// make its size one larger than maxHeads
int counts[] = new int [maxHeads + 1];

// step 2:
// initialize all of the values in the array to 0
for (int arrayindex = MIN_HEADS; arrayindex <= maxHeads; arrayindex ++)
counts[arrayindex] = 0;


// step 3:
// flip the coin for n sets with nFlips flips per set
// count the number of heads in each set (heads = 1, tails = 0)

// Using the value nSets (the number of sets of flips) and nFlips
// (the number of coin flips per set) from the user, execute a loop nSets times.
// Each time through this outer loop, your code starts with sum equal to zero and
// loops for nFlips times calling the flip method of myCoin, adding either one for a
// head or zero for a tail to the sum. After the inner loop completes, the outer loop
// uses the sum calculated by the inner loop as an array index, and increments the
// value of that element in the counts array.

for (int i = 0; i < nSets; i++) {
int sum = 0;
for (int j = 0; i < nFlips; j++)
{
sum = sum + (myCoin.flip()? 1: 0);
}

// step 4:
// print out the estimated probabilities of all heads and all tails
System.out.println ((float) counts [MIN_HEADS] / nSets);


// step 5:
// find largest number in counts array for scaling length of bars

int maxCount = 0;
for (int i = MIN_HEADS; i < maxHeads +1; i++)
{
if (maxCount <= counts )
{
maxCount = counts ;
}


// step 6:
// scale data in counts array to maximum length of bars
// add 0.5 to round off instead of truncate in conversion to int
for (int i = MIN_HEADS; i < (maxHeads +1); i++)
counts = ((double)(count * maxLength / myCount) +.5);

// step 7:
// draw horizontal bar graph (one line per heads value)
for (int i = MIN_HEADS; i <= maxHrads +2; i++)
System.out.print("Heads Counts " + i);
{
for (int j = 0; j < counts ; j++)
{
System.out.print ("x");

}
System.out.println (counts );
}
// step8:
// draw vertical bar graph (one column per heads value)
for (int v = maxHeads; v >= 1; v--)
{
System.out.print ("Count " +v+ " ");
for (int u = 0; u < maxHeads +1; u++)
{
if (counts >= v)
System.out.print(" * ");
else
System.out.print (" ");

System.out.println ("");
}

}
}
// function to calculate factorial of n
public static int factorial(int n)
{
{
int factorial = 1;

// write the code for a loop to calculate factorial of n here

//**while (counter > 1)
//**factorial *= --counter; // Multiply the decremented number.


return factorial;
}
}
}

 

This really belongs in the "Development" forum. What is the error message you're getting?

Peace...

 

PHP:

import java.util.Scanner;

public class Histogram
{

    private static final int MIN_HEADS = 0; // minimum number of heads per set

    /**
    * main method:
    * ask the user how many sets of coin flips and how many flips per set
    * count occurances of heads in user specified number of sets of coin flips
    * draw a horizontal and vertical histogram of the number of heads
    */
    public static void main(String[] args)
    {
        // set up to get user input
        Scanner scan = new Scanner(System.in);
        // ask user for the number of sets of coin flips
        System.out.println("How many sets of coin flips do you want?");
        int nSets = scan.nextInt();
        // ask user for the number of coin flips per set
        System.out.println("How many coin flips per set do you want?");
        int nFlips = scan.nextInt();
        // maximum number of heads that can occur is number of flips
        int maxHeads = nFlips;
        // calculate maximum length of histogram bars based on number of flips per set
        // based on finding the number of combinations for half heads / half tails
        // n!
        // formula is ----------- with r = n/2
        // r! (n-r)!
        int maxLength = factorial (nFlips) /
        (factorial (nFlips / 2) * factorial (nFlips - nFlips / 2));
        // instantiate a coin object named myCoin
        Coin myCoin = new Coin();
        // step 1:
        // declare an int array named "counts" to count coin flip occurences
        // make its size one larger than maxHeads
        int counts[] = new int [maxHeads + 1];
        // step 2:
        // initialize all of the values in the array to 0
        for (int arrayindex = MIN_HEADS; arrayindex <= maxHeads; arrayindex ++)
        counts[arrayindex] = 0;
        // step 3:
        // flip the coin for n sets with nFlips flips per set
        // count the number of heads in each set (heads = 1, tails = 0)
        // Using the value nSets (the number of sets of flips) and nFlips
        // (the number of coin flips per set) from the user, execute a loop nSets times.
        // Each time through this outer loop, your code starts with sum equal to zero and
        // loops for nFlips times calling the flip method of myCoin, adding either one for a
        // head or zero for a tail to the sum. After the inner loop completes, the outer loop
        // uses the sum calculated by the inner loop as an array index, and increments the
        // value of that element in the counts array.
        for (int i = 0; i < nSets; i++)
        {
            int sum = 0;
            for (int j = 0; i < nFlips; j++)
            {
                sum = sum + (myCoin.flip()? 1: 0);
            }
            // step 4:
            // print out the estimated probabilities of all heads and all tails
            System.out.println ((float) counts [MIN_HEADS] / nSets);
            // step 5:
            // find largest number in counts array for scaling length of bars
            int maxCount = 0;
            for (int i = MIN_HEADS; i < maxHeads +1; i++)
            {
                if (maxCount <= counts [i])
                {
                    maxCount = counts [i];
                }
                // step 6:
                // scale data in counts array to maximum length of bars
                // add 0.5 to round off instead of truncate in conversion to int
                for (int i = MIN_HEADS; i < (maxHeads +1); i++)
                counts [i] = ((double)(count [i] * maxLength / myCount) +.5);
                // step 7:
                // draw horizontal bar graph (one line per heads value)
                for (int i = MIN_HEADS; i <= maxHrads +2; i++)
                System.out.print("Heads Counts " + i);
                {
                    for (int j = 0; j < counts [i]; j++)
                {
                System.out.print ("x");
            }
            System.out.println (counts [i]);
        }
        // step8:
        // draw vertical bar graph (one column per heads value)
        for (int v = maxHeads; v >= 1; v--)
        {
            System.out.print ("Count " +v+ " ");
            for (int u = 0; u < maxHeads +1; u++)
            {
                if (counts [u] >= v)
                    System.out.print(" * ");
                else
                    System.out.print (" ");
                System.out.println ("");
            }
        }
    }
    // function to calculate factorial of n
    public static int factorial(int n)
    {
    {
        int factorial = 1;

        // write the code for a loop to calculate factorial of n here

        //**while (counter > 1)
        //**factorial *= --counter; // Multiply the decremented number.


        return factorial;
    }
    }
}


Note: [PHP /PHP] tags help make code readable.

The first thing I have to ask is why there are an extra set of brackets for that function {{}}