I’m working on a lottery application:
- The user enters 5 numbers between 1-25 that get saved to an array
- Another array gets filled with 5 random numbers between 1-25
I’ve gotten to a point where I can print out both of the arrays, but I have no clue on how to compare them to see if the user won, and on how many numbers.
namespace ConsoleApp14
{
internal class Program
{
static void Main(string[] args)
{
int[] userBingo = new int[5];
Console.WriteLine("Var vänligt och skriv in 5 tal mellan 1-25: ");
for (int i = 0; i < userBingo.Length; i++)
{
int inputBingo;
do
{
string input = Console.ReadLine();
if (!int.TryParse(input, out inputBingo))
{
Console.WriteLine("Felaktig inmatning! Var vänlig och försök igen.");
continue;
}
if (inputBingo < 1 || inputBingo > 25)
{
Console.WriteLine("Var vänlig och skriv in ett tal mellan 1-25. ");
continue;
}
userBingo[i] = inputBingo;
break;
} while (true);
}
Console.WriteLine("Här är dina tal!");
foreach (int i in userBingo)
{
Console.WriteLine(i);
}
Console.WriteLine();
Console.WriteLine("Och de vinnande talen är: ");
int[] winningNumber = new int[5];
Random random = new Random();
for (int i = 0; i < winningNumber.Length; i++)
{
winningNumber[i] = random.Next(1,26);
}
foreach (int i in winningNumber)
{
Console.WriteLine(i);
}
}
}
}
I’m not actually sure what to try, I’ve only recently started learning about arrays and know how to create them, but not compare them.
2
If order matters you can use sequenceEquals
userBingo.SequenceEquals(winningNumber);
If numbers can be in any order you could first order both lists to ensure consistent ordering:
Array.Sort(userBingo);
Array.Sort(winningNumber);
userBingo.SequenceEquals(winningNumber);
If numbers are guaranteed to be unique you could also use HashSet:
userBingo.HashSet().SetEquals(winningNumber);
Do note that your teacher may expect something you write yourself, and not simply using library methods to do all the heavy lifting. One way to do order insensitive comparing yourself is:
- Declare an array of length 26, lets call it histogram
- Loop thru both arrays, use the array value as the histogram index and increment that value, i.e.
histogram[userBingo[i]]+=1 - Loop thru the histogram, if any values are odd the arrays are not equal.
To compare the two arrays and determine if the user has won, and on how many numbers, you can
Create a function that checks if a number exists in an array.
static bool IsNumberInArray(int[] array, int number)
{
foreach (int n in array)
{
if (n == number)
{
return true;
}
}
return false;
}
Iterate through the userBingo array and check if each number exists in the winningNumber array using the function created in step 1.
Keep a count of the matched numbers.
// Check how many numbers from userBingo exist in winningNumber
foreach (int userNumber in userBingo)
{
if (IsNumberInArray(winningNumber, userNumber))
{
matchedNumbers++;
}
}
After iterating through all the user’s numbers, check the count and determine if the user has won based on your game rules.