CODEWITHSUNDEEP
javaarraysrandomhashmaphashset
TheSTARplow
TheSTARplow

Reputation: 13

Counting how often a number in a Hashset has been picked

Here my code until now: 

 public void lottoGame() {        
      HashSet<Integer> dups = new HashSet<Integer>();  

      for(int howMany = 1; howMany <= 6; howMany++) {
           int lottoNumber = lottoNum.nextInt(49) + 1;

           while(dups.contains(lottoNumber)) {
                lottoNumber = lottoNum.nextInt(49) + 1;
           } 

           dups.add(lottoNumber);
           randomLotto[howMany] = lottoNumber;

           System.out.println(lottoNumber);

    }
    for(int counter : dups) {
        numberCount[counter]++; //to store the counting of random numbers
    } 

    for(int counting = 1; counting < numberCount.length; counting++) {
        System.out.println(counting + " occurs " + numberCount[counting] + " times");
    }
}

So basically, what I did was create a hashset and put in 6 random numbers. In my last 2 for-loops I'm trying to count how often I draw which number and print that out. The problem is, it starts with the 3rd field when printing out, for whatever reason. Does anyone know why?

Upvotes: 0

Views: 151

Answers (2)

urag
urag

Reputation: 1258

I would suggest using map it is much simpler here look at this example 

  public static void lotoGame() {
    Random rand = new Random();
    Map<Integer, Integer> loto = new HashMap<>();
    while (loto.keySet().size() < 6) {
        int lottoNumber = rand.nextInt(49) + 1;
        loto.compute(lottoNumber, (key, value) -> value == null ? 1 : ++value);
    }

    loto.forEach((key,value)->{
        System.out.println(key + " occurs " + value + " times");
    });
}

Upvotes: 0

Demogorii
Demogorii

Reputation: 676

Here is the example you gave. The output I have is correct. Verify your settings or other code you might not show us.

Look at : Is there a limit on the maximum of number of lines which can be printed to console by BlueJ?

class Test
{
    public void lottoGame()
    {
        int[] randomLotto = new int[50];
        int[] numberCount = new int[50];
        Random lottoNum = new Random();
        HashSet<Integer> dups = new HashSet<Integer>();

        for (int howMany = 1; howMany <= 6; howMany++)
        {
            int lottoNumber = lottoNum.nextInt(49) + 1;

            while (dups.contains(lottoNumber))
            {
                lottoNumber = lottoNum.nextInt(49) + 1;
            }

            dups.add(lottoNumber);
            randomLotto[howMany] = lottoNumber;

            System.out.println(lottoNumber);

        }
        for (int counter : dups)
        {
            numberCount[counter]++; //to store the counting of random numbers
        }
        for (int counting = 1; counting < numberCount.length; counting++)
        {
            System.out.println(counting + " occurs " + numberCount[counting] + " times");
        }
    }

    public static void main(String[] args)
    {
        new Test().lottoGame();
    }
}

Output :

43
27
38
30
14
8
1 occurs 0 times
2 occurs 0 times
3 occurs 0 times
4 occurs 0 times
5 occurs 0 times
6 occurs 0 times
7 occurs 0 times
8 occurs 1 times
9 occurs 0 times
10 occurs 0 times
11 occurs 0 times
12 occurs 0 times
13 occurs 0 times
14 occurs 1 times
15 occurs 0 times
16 occurs 0 times
17 occurs 0 times
18 occurs 0 times
19 occurs 0 times
20 occurs 0 times
21 occurs 0 times
22 occurs 0 times
23 occurs 0 times
24 occurs 0 times
25 occurs 0 times
26 occurs 0 times
27 occurs 1 times
28 occurs 0 times
29 occurs 0 times
30 occurs 1 times
31 occurs 0 times
32 occurs 0 times
33 occurs 0 times
34 occurs 0 times
35 occurs 0 times
36 occurs 0 times
37 occurs 0 times
38 occurs 1 times
39 occurs 0 times
40 occurs 0 times
41 occurs 0 times
42 occurs 0 times
43 occurs 1 times
44 occurs 0 times
45 occurs 0 times
46 occurs 0 times
47 occurs 0 times
48 occurs 0 times
49 occurs 0 times

Upvotes: 1

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