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Program to find the product of odd numbers from 1 to n and the sum of the squares of even numbers according to the number n entered from the keyboard [closed]

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I'm new to the programming world and I'm learning C#. I have an algorithm given to me in expression language and I need to do it with C# .NET Framework console application, but I'm not very good at it. Can you help?
Here's the algorithm I'm talking about;
Start
int toplam, carpım, karetoplam
toplam=0
carpım=1
Read N
6.Cycle I=1, N, 1
if(N%2==1)
toplam=toplam+I
carpım=carpım*I
else
karetoplam=karetoplam+(I*I)
if over
cycle over
Cw toplam
Cw carpım
Cw karetoplam
Done

I only understood the title of your post not the text ;)
Code is untested. Could be optimized to 1 for-loop in 1 method.
Product of oddnumber from 1 to n?
long GetProductsOfOddNumbers(int n) {
var product = 1L;
for (var i = 1; i <= n; i++) {
if (i % 2 == 0) continue;
product *= i;
}
return product;
}
Sum of squares of even numbers from 1 to n?
long GetSumOfSquaresOfEvenNumbers(int n) {
var sum = 0L;
for (var i = 1; i <= n; i++) {
if (i % 2 != 0) continue;
sum += (i * i);
}
return sum ;
}

C# Raise number to power [closed]

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I recently stumbled upon a weird bug in one of my programs.
for (int i = 0; i < bitArray.Length; i++)
{
if (bitArray[i])
{
returnValue = returnValue + 2 ^ (7 - i);
}
}
In the snippet above, if returnValue = 0, by the time it reaches a set bit at i = 7, the resulting output is 2, which makes no sense (2^0 should be 1). However if I replace the code with:
returnValue = returnValue + Convert.ToInt32(Math.Pow(2,(7 - i)));
It is evaluated correctly to returnValue = 1
The problem is solved by using Math.Pow(), but I would very much like to know why it happens in the initial code.

In C# (and many other languages) the ^ operator is the boolean logical XOR.
See this document for more information about boolean operators in C#.

In addition to the other answers, it is probably simplest if you just use the C# left-shift operator <<, assuming bitArray.Length is less than or equal to 8:
for (int i = 0; i < bitArray.Length; i++)
{
if (bitArray[i])
{
returnValue = returnValue + 1 << (7 - i);
}
}
If returnValue is a float type and the intention is to allow negative powers of 2, then a slight change yields:
for (int i = 0; i < bitArray.Length; i++)
{
if (bitArray[i])
{
returnValue = returnValue + ((7-i) >= 0) ? 1 << (7 - i) : 1.0 / ((1 << (7 - i));
}
}
although in this case Math.Pow(2, 7 - i) is much cleaner.
for (int i = 0; i < bitArray.Length; i++)
{
if (bitArray[i])
{
returnValue = returnValue + Math.Pow(2, 7 - i);
}
}

As #IshaySela and #Adomas have said, ^ is a bollean logical XOR.
But in-order to do what you want to do without using math.pow() you can just make an if condition to check if the power is equal ZERO or not.
if (bitArray[i]) {
if ((7 - i) == 0){
//returnValue += 1;
}
else{
//returnValue += 2 ^ (7 - i);
}
}

Errors when using quicksort to sort a double [closed]

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I have a string array that I convert to double, I pass it into the following quicksort algorithm and get multiple errors saying I cannot onvert double to int despite having a double array. Left and right are 0 and arr.Length - 1 respectively.
public static double[] quick_Sort(double[] arr, double left, double right)
{
double i, j;
double pivot, temp;
i = left;
j = right;
pivot = arr[(left + right) / 2];
do
{
while ((arr[i] < pivot) && (i < right)) i++;
while ((pivot < arr[j]) && (j > left)) j--;
if (i <= j)
{
temp = arr[i];
arr[i] = arr[j];
arr[j] = temp;
i++;
j--;
}
} while (i <= j);
if (left < j) quick_Sort(arr, left, j);
if (i < right) quick_Sort(arr, i, right);
return arr;
}

The problem is that you are using doubles for your array indexes -- which are supposed to be ints, e.g.
arr[i]
You need to use int values for your indexes, e.g.:
int i;
i = Convert.ToInt32(left);
Or just use int instead of double for your all your variables (depending on how your program works). I'm not sure what's best without more information.

divide the money value to zero? [closed]

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i have a problem to divide the money value to "0".
i build accounting software, with a shrinking asset.
example, i have a value 1000000.
i would divide it into 3.
1000000 / 3 = 333333,33333333333333333333333
the question is, i would to do this:
step 1 :1000000 - 333333,33333333333333333333333 =
666666,66666666666666666666667
step 2 :666666,66666666666666666666667 -
333333,33333333333333333333333 = 333333,33333333333333333333334
step 3 :333333,33333333333333333333334 -
333333,33333333333333333333333 =
0,00000000000000000000001
example code
decimal value = 100;
int divider = 3;
decimal x = value / divider;
for (int i = 0; i < divider; i++)
{
value = value - x;
}
the result, value = 0,000000000000000000000000001 .
yeah, that is a problem.
that a money value, i would divide to zero.
I've tried using math method like a "math.floor" at each step (on loop).
the result value is -2.
i know i can using "math.floor" method for the final result. but i don't, because i want to do step to step (on loop.)
what should i do?
thanks

You should consider multiplying your 1/3 by 1, 2, or 3 instead of subtracting the previous number. Something like this should work:
var originalAmount = 1000000d;
var thirdOfOriginal = originalAmount / 3;
Console.WriteLine("Original number ... {0}", originalAmount);
Console.WriteLine("Original - 1/3 .... {0}", (originalAmount - (thirdOfOriginal * 1)));
Console.WriteLine("Original - 2/3 .... {0}", (originalAmount - (thirdOfOriginal * 2)));
Console.WriteLine("Original - 3/3 .... {0}", (originalAmount - (thirdOfOriginal * 3)));
// Output
// Original number ... 1000000
// Original - 1/3 .... 666666.666666667
// Original - 2/3 .... 333333.333333333
// Original - 3/3 .... 0
This could be written more generically as:
private static List<decimal> GetAmounts(decimal originalNumber, int numberOfDivisions)
{
var amounts = new List<decimal>();
if (numberOfDivisions > 0)
{
var fraction = originalNumber / numberOfDivisions;
for (int i = 1; i <= numberOfDivisions; i++)
{
amounts.Add(originalNumber - (fraction * i));
}
}
return amounts;
}

Algo reversing c# [closed]

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I have some algorithm written in c#:
int num3 = 260005;
string text = this.textBox1.Text;
int length = text.Length - 4;
int num5 = ((Convert.ToInt32(text.Substring(4, length)) - 0x7d1) / 2) - 0x7d1;
if (num3 == num5)
{
do somthing!!!
}
Can somebody explain how to get correct input for textBox1? I try some math but i stuck.
I see now. I was confused with 4 character that are trow away.

This code will match what you are looking for... This is because you are throwing away the leading FOUR characters of the text box and then doing a simple equation of ((x - 2001) / 2) - 2001 = 260005 therefore x = 526013:
int num3 = 260005;
string text = "XXXX526013";
int length = text.Length - 4;
int num5 = ((Convert.ToInt32(text.Substring(4, length)) - 0x7d1) / 2) - 0x7d1;
if (num3 == num5)
{
Console.WriteLine("Match!");
}
else
{
Console.WriteLine("No Match! {0}", num5);
}

You can simply reverse your algorithm:
string text = "asdf" + (((num3 + 0x7d1)*2) + 0x7d1);