Develop Reference

C# slotmachine supposed to keep one continuous score, somehow keeps multiple separate scores

I've been working on a slotmachine in C# for practise purposes, and the machine itself works as intentional. The points system, however, does not. The game starts at 100 points, and if, for example, the player lose three 5-point bets and wins 40 points on the fourth bet, the expected points would be 100-20+40=120 points. For some reason however, the code treats ALL the previous bets as being 40 point wins as well, bringing the total to 100-20+160=240 points. If the player then lose the fifth 5-point bet, the score jumps to 75.
I start by setting the 'points' value to 100, which should then update everytime the 'game()' function is called upon.
public static void Main()
{
int points = 100;
int num = 0;
Console.WriteLine("Welcome to 'Slotmachine'!\nThe aim of this game is to get a score of 1000 or higher.\nYou lose if you reach 0 or lower.\nPress enter to play");
Console.ReadLine();
Console.Clear();
points = points + game(100);
while(points<1000 && points>0)
{
num = num + 1;
Console.WriteLine("You've played for "+num+" number of round(s)");
points = points + game(points);
}
}
The 'game()' funtion returns the players winnings, which is used to update the 'points' value (Suspect nr 1?).
Inside the game function I have a 'usrbet' which takes an input from the user (1-10), which is then fed into the 'slots()' function to determine the winnings (the 'points' that are fed from 'Main()' are checked to see what the user can bet)
Console.WriteLine("Here are your current points: "+points+"\nHow much would you like to bet?\nmin bet: 1\nmax bet: 10");
try
{
usrbet = Convert.ToInt32(Console.ReadLine());
}
catch
{
usrbet = 1;
}
winnings = slots(usrbet);
int RetWin = winnings - usrbet;
return RetWin;
Here's what the 'slots()' function does, with some examples of the winnings calculations
public static int slots(int usrbet)
{
int Win;
int x;
int y;
int z;
Random slot = new Random();
x = slot.Next(2,10);
y = slot.Next(2,10);
z = slot.Next(2,10);
Console.WriteLine(x+""+y+""+z);
Example 1
if(x == y && y == z && x== 7)
{
Win = usrbet*250;
Console.WriteLine("WOW! That's incredible, you just won "+Win+"!");
}
Example 2
else if(x == z)
{
Win = usrbet*5;
Console.WriteLine("Congratulations, you win "+Win+".");
}
Example 3
else
{
Win = 0;
Console.WriteLine("Ah, bummer. You didn't win anything this time.");
}
After that, the 'Win' value is sent back to 'game()', updating 'winnings'.
I apologize for poor formatting of the question. I'll include a link to the code, in case my problem lies elsewhere in the code: https://dotnetfiddle.net/D5TwL0
I've tried making arrays of the 'bet' and 'usrbet' variables, in an attempt to have a "new" value to update the 'points' with at every run of 'game()', but that changed absolutely nothing other than limiting how many times 'game()' can run before getting an overflow error.

It turns out that the problem wasn't with the code, but with the compiler. Dotnetfiddle is where I made the code and had the issue, but trying it in another compiler, it managed to count just fine.

Best way to choose two random ints to assign values to

I am creating a Dungeons and Dragons Character Creator. There is a randomize feature that is going to create a complete character sheet. There is a part that I have gotten to and I am not quite sure the best way to proceed.
The way I have the racial modifiers set up is with if statements. Here is an example.
if (raceInt == 0 || raceInt == 2 || raceInt == 10)
{
raceStrMod = 2;
}
if (raceInt == 3 || raceInt == 4 || raceInt == 5 || raceInt == 11 || raceInt == 12)
{
raceDexMod = 2;
}
However there are races that have modifiers that let you select two stats to add a modifier to, such as Strength or Dexterity. What would be the best way to select two random ints for just those races?
For example, the half-elf race which would get +2 to Dex and then +1 to two other random stats. So I need to find a way to randomly select two of the remaining ints to make the value = 1.
My race mod ints are initialized as
int raceStrMod = 0;
int raceDexMod = 0;
int raceConMod = 0;
int raceIntMod = 0;
int raceWisMod = 0;
int raceChaMod = 0;
Then the if statements assign a value dependent on which race was randomly selected.
Thank you all for the input! This is how I ended up coding it
if (raceInt == 9)
{
int randomX = rnd.Next(1, 5);
int randomY = rnd.Next(1, 5);
int attempts = 0;
while (randomX == randomY && attempts < 10)
{
randomY = rnd.Next(1, 5);
attempts++;
}
//if they are still not unique after 10 attempts
if (randomX == randomY)
{
if (randomX == 5)
randomY = 1;
else
randomY = randomX + 1;
}
int[] randomNumbers = { randomX, randomY };
foreach (int i in randomNumbers)
{
switch (i)
{
case 1:
raceStrMod = 1;
break;
case 2:
raceDexMod = 1;
break;
case 3:
raceConMod = 1;
break;
case 4:
raceIntMod = 1;
break;
case 5:
raceWisMod = 1;
break;
}
}
}

Has your class introduced you to enum types yet? If not, is there any restriction on your final project with respect to using language features that weren't taught in the class?
Your question is arguably too broad, as there are many different ways to address this sort of thing even in real-world code, and the classroom context introduces potential roadblocks that while might constrain the question, being unknown they make it impossible to know what answer is actually going to work for you.
That said…
Ignoring the classroom aspect and focusing only on the problem itself, I would use enum types and dictionaries for this sort of thing. For example:
enum Attribute
{
Strength,
Dexterity,
Constitution,
Charisma,
Intelligence,
Wisdom,
Count, // must always be last
}
Dictionary<Attribute, int> modifiers = new Dictionary<Attribute, int>();
Then you can pick a random attribute like (assuming you have a random variable referencing a Random object…don't make the classic newbie mistake of creating a new Random object every time you want to pick a new random number):
Attribute attributeToModify = (Attribute)random.Next((int)Attribute.Count);
And you can store that selection like:
modifiers[attributeToModify] = 1;
This can be used to store however many modifiers you like. You can encapsulate that in an object representing the character itself, or you could put it into a separate AttributeModifiers class. One advantage of doing the latter would be that if you have modifiers that come from different sources, you can track that in the character object as a list of AttributeModifier instances, each in turn keeping track of what the actual source of those modifiers are.
This just barely scratches the surface. As I noted, the question itself is fairly broad. But I strongly recommend using the available language features to ensure that your variables represent things in a type-specific way, rather than just using int values for things that aren't really integers, and to use collection classes that more correctly represent the semantics of what your code is intended to do.
Note that this also means you probably should have an enum type for the races. E.g.:
enum Race
{
Dwarf,
Elf,
HalfElf,
Halfling,
HalfOrc,
Human,
// etc.
}
And your chain of if statements is probably better represented as a switch:
Attribute racialMod;
switch (race)
{
case Human:
case Halfling:
// etc.
racialMod = Attribute.Strength;
break;
case Elf:
case HalfElf:
// etc.
racialMod = Attribute.Dexterity;
break;
}
modifiers[racialMod] = 2;
Something like that. The point is to make sure the code reads more like what the original specification would say (if you actually had written one). This will make the code easier to understand, and it will be less likely for you to put bugs in the code (e.g. you accidentally type the wrong magic, unnamed integer).

I am creating a Dungeons and Dragons Character Creator.
That's a fun beginner project; I did the same when I was learning to program.
I need to find a way to randomly select two of the remaining...
You need to find two distinct values, call then x and y. The solution you've arrived at is:
Generate x
Try to generate y ten times
If no attempt succeeded to find a distinct y, hard-code a choice.
That works, and you almost never have to use the hard-coded choice. But I thought you might be interested to know that there is an easier way to generate two distinct numbers. Let's suppose we want two distinct numbers from 0, 1, 2, 3 or 4. (Obviously if you want a different range, say, 1 through 5, you can solve that problem by generating two distinct numbers 0->4 and then adding one to each.)
The improved algorithm is:
Choose x between 0 and 4 as usual.
Choose n between 1 and 4.
y = (x + n) % 5;
Think about it this way. Suppose we make a list like this:
0, 1, 2, 3, 4, 0, 1, 2, 3
We randomly choose x from the first five entries on the list, and then we choose y by stepping forwards between 1 and 4 steps. Since the list does not repeat in one to four steps, we know that we'll get two unique elements. The math does the equivalent of that.
You could similarly have used % in your program:
if (randomX == 5)
randomY = 1;
else
randomY = randomX + 1;
could be written
randomY = randomX % 5 + 1
If you're unfamiliar with %, it is the remainder operator. It is the complement of the / operator. The rule is:
int x = whatever;
int y = whatever;
int r = x % y;
is the same as:
int r = x - (x / y) * y;
That is, it is the remainder when x is divided by y. Keep in mind that the remainder can be negative!

(Disclaimer: I don't love this option, but couldn't think of another way other than reflection which is even nastier)
You could define a class that masks the fact that all of the mods are stored as an array and therefore can be indexed using a random number.
Something like the following:
public class StatMods
{
public int RaceStrMod { get { return this.mods[0]; } set { this.mods[0] = value; } }
public int RaceDexMod { get { return this.mods[1]; } set { this.mods[1] = value; } }
public int RaceConMod { get { return this.mods[2]; } set { this.mods[2] = value; } }
public int RaceIntMod { get { return this.mods[3]; } set { this.mods[3] = value; } }
public int RaceWisMod { get { return this.mods[4]; } set { this.mods[4] = value; } }
public int RaceChaMod { get { return this.mods[5]; } set { this.mods[5] = value; } }
private readonly int[] mods;
private static readonly Random rand = new Random();
public StatMods()
{
this.mods = new int[6];
}
public void ApplyRandomMod(int modification)
{
this.mods[rand.Next(0, 6)] += modification;
}
}

C# - Stuck with use of list and array

I have been practicing c# nowadays and decided to write a code that converts any decimal to any base representation for practice purpose. And i have some troubles. Since i want to practice i decided to do it with an additional function where calculations take place. First i wanted to use an array to keep my result. But since ,at the beginning, i do not know the length of the array i could not define it.So i decided to use list(somehow i assumed undeclared slots are 0 as default). This is what i end up with.
class MainClass
{
static double number;
static double baseToConvert;
static int counter = 0;
static List<double> converted = new List<double>();
public static void Main(string[] args)
{
Console.WriteLine("Enter a decimal");
number = double.Parse(Console.ReadLine());
Console.WriteLine("Enter a base you want to convert to");
baseToConvert = double.Parse(Console.ReadLine());
ConverterToBase(number);
for (int i = converted.Count - 1; i >= 0; i--)
{
Console.WriteLine(converted[i]);
}
Console.ReadLine();
}
public static void ConverterToBase(double x)
{
double temp = x;
while (x >= baseToConvert)
{
x /= baseToConvert;
counter++;
}
converted[counter] = x;
counter = 0;
if (temp - x * Math.Pow(baseToConvert, Convert.ToDouble(counter)) >= baseToConvert)
{
ConverterToBase(temp - x * Math.Pow(baseToConvert, Convert.ToDouble(counter)));
}
else
{
converted[0] = temp - x * Math.Pow(baseToConvert, Convert.ToDouble(counter));
}
}
}
But after i write inputs console gets stuck without an error. My guess is that since i do not have any elements in the list " converted[counter] " does not make sense. But i do not know maybe the problem is somewhere else.
My question is not about the way i calculate the problem(Of course any suggestions are welcomed). I just want to know what i am doing wrong and how i can handle such situation(unknown array size , use of list , accessing a variable,array,.. etc from another method... ).
Thanks.

My previous answer was wrong as pointed out by #Rufus L. There is no infinite for loop. However upon further review, there seems to be an infinite recursion going on in your code in this line:
if (temp - x * Math.Pow(baseToConvert, Convert.ToDouble(counter)) >= baseToConvert)
{
ConverterToBase(temp - x * Math.Pow(baseToConvert, Convert.ToDouble(counter)));
}
ConverterToBase calls itself and there seems to be no base case nor return statement to end the recursion.

In the method named "ConverterToBase(double x)" you want to set value of 0 element. But you didn't add any element. The converted is Empty.
Firstly add value or values to your list.

What wrong with this implement of this arcsine approximate in C#

This is a formula to approximate arcsine(x) using Taylor series from this blog
This is my implementation in C#, I don't know where is the wrong place, the code give wrong result when running:
When i = 0, the division will be 1/x. So I assign temp = 1/x at startup. For each iteration, I change "temp" after "i".
I use a continual loop until the two next value is very "near" together. When the delta of two next number is very small, I will return the value.
My test case:
Input is x =1, so excected arcsin(X) will be arcsin (1) = PI/2 = 1.57079633 rad.
class Arc{
static double abs(double x)
{
return x >= 0 ? x : -x;
}
static double pow(double mu, long n)
{
double kq = mu;
for(long i = 2; i<= n; i++)
{
kq *= mu;
}
return kq;
}
static long fact(long n)
{
long gt = 1;
for (long i = 2; i <= n; i++) {
gt *= i;
}
return gt;
}
#region arcsin
static double arcsinX(double x) {
int i = 0;
double temp = 0;
while (true)
{
//i++;
var iFactSquare = fact(i) * fact(i);
var tempNew = (double)fact(2 * i) / (pow(4, i) * iFactSquare * (2*i+1)) * pow(x, 2 * i + 1) ;
if (abs(tempNew - temp) < 0.00000001)
{
return tempNew;
}
temp = tempNew;
i++;
}
}
public static void Main(){
Console.WriteLine(arcsin());
Console.ReadLine();
}
}

In many series evaluations, it is often convenient to use the quotient between terms to update the term. The quotient here is
(2n)!*x^(2n+1) 4^(n-1)*((n-1)!)^2*(2n-1)
a[n]/a[n-1] = ------------------- * --------------------- -------
(4^n*(n!)^2*(2n+1)) (2n-2)!*x^(2n-1)
=(2n(2n-1)²x²)/(4n²(2n+1))
= ((2n-1)²x²)/(2n(2n+1))
Thus a loop to compute the series value is
sum = 1;
term = 1;
n=1;
while(1 != 1+term) {
term *= (n-0.5)*(n-0.5)*x*x/(n*(n+0.5));
sum += term;
n += 1;
}
return x*sum;
The convergence is only guaranteed for abs(x)<1, for the evaluation at x=1 you have to employ angle halving, which in general is a good idea to speed up convergence.

You are saving two different temp values (temp and tempNew) to check whether or not continuing computation is irrelevant. This is good, except that you are not saving the sum of these two values.
This is a summation. You need to add every new calculated value to the total. You are only keeping track of the most recently calculated value. You can only ever return the last calculated value of the series. So you will always get an extremely small number as your result. Turn this into a summation and the problem should go away.

NOTE: I've made this a community wiki answer because I was hardly the first person to think of this (just the first to put it down in a comment). If you feel that more needs to be added to make the answer complete, just edit it in!
The general suspicion is that this is down to Integer Overflow, namely one of your values (probably the return of fact() or iFactSquare()) is getting too big for the type you have chosen. It's going to negative because you are using signed types — when it gets to too large a positive number, it loops back into the negative.
Try tracking how large n gets during your calculation, and figure out how big a number it would give you if you ran that number through your fact, pow and iFactSquare functions. If it's bigger than the Maximum long value in 64-bit like we think (assuming you're using 64-bit, it'll be a lot smaller for 32-bit), then try using a double instead.

How Can I Reduce Lines with Using Switch-Case Properly

I'm working on a Blackjack game project. I have a helper()method for helping user for their acts. For example:
dealer's up card is: 8
player's hand total is: 16
Player is not sure, should he hit or stay. helper() function takes action in here.
It's basically counts the number of good cards on deck (playerTotal + goodcard <= 21)
So I'm thinking about to do it in this way (pseudo code)
public void helper() {
remain = 21 - playerTotal;
if (remain == 1) {
for (int i = 0; i < deck.last(); i++) {
switch (deck[i]) {
case A: numOfGood += 1
default: numOfBad +=1
}
}
}
else if (remain == 2) {
for (....) {
switch (deck[i]) {
case A: numOfGood += 1
case 2: numOfGood += 1
default: numOfBad +=1
}
}
}
//goes like this
}
I need to build a switch-case and for loop for all cards(A,2,3,4,5,6,7,8,9,J,K,Q,K) but it seems like a huge mess. How can I reduce the number of lines by doing something different?

First write a GetValue method that can compute the (minimum) numeric value for a card. You can implement it with a switch or however else you want:
public static int GetValue(char card)
{
//...
}
Once you have that the implementation of your method becomes far shorter and simpler:
foreach(var card in deck)
if(GetValue(card) <= remain)
numOfGood++;
else
numOfBad++;
Also note that you could just count the number of good or bad cards, and use the total remaining cards to compute the other, if needed.
var oddsOfSuccessfulHit = deck.Count(card => GetValue(card) <= remain) /
(double) deck.Count;

You could use a HashSet, its probably a little more efficient to use a switch but if you want to save lines ...
var goodCards = new HashSet<char>(new[] { 'A', '2' });
then something like,
var numOfGood = deck.Count(card => goodCards.Contains(card));
var numOfBad = deck.Count - numOfGood;

Alternatively since the logic of card values cannot change, there is no need to code it - just store it as data.
struct CardEffect
{
public string CardGlyph;
public int MinValue;
public int MaxValue;
}
... load from XML file or some other location and load into ...
public Dictionary<string, CardEffect> cardValues;
Then use the logic Servy has suggested.