# Use every second integer • ### Question

• I cant explain what i want exactly but heres an example of what i want to do.

Its not homework, its a personal project. I gave up on coding during my first year, so im not very good at it.

Would appreciate the help!

```//Using Number 800121500908(5) as an example:

//Add all the digits in the odd positions (excluding last digit).
//8 + 0 + 2 + 5 + 0 + 0 = 15  .............................

//Move the even positions into a field and multiply the number by 2.
//011098 x 2 = 22196  .....................................

//Add the digits of the result in .
//2 + 2 + 1 + 9 + 6 = 20  .................................

//15 + 20 = 35  ...........................................

//Subtract the second digit of (i.e. 5) from 10. The number must tally with the last number in the example(5).
//If the result is 2 digits, the last digit is used to compare against the last number in the example Number.
//If the answer differs, the example number is invalid.```

Mr.SMP

Tuesday, May 13, 2014 1:28 PM

• I have manged to reach till .

``` long input = 800121500908;
Console.WriteLine(string .Format("[Input] is {0}",input));

string inputAsString = input.ToString();

int index = 0;
int oddDigitsS =0;
long evenDigitsNumber;
long evenDigitsNumberDoubled;
string evenDigitsString = string.Empty;

foreach (char digitChar in inputAsString)
{
index++;

if (index % 2 == 1)
{
oddDigitsS += int.Parse(digitChar.ToString());
}
else
{
evenDigitsString+= digitChar.ToString();
}
}
Console.WriteLine(string .Format(" is {0}",oddDigitsS));

evenDigitsNumber = long.Parse(evenDigitsString);

evenDigitsNumberDoubled = evenDigitsNumber * 2;
Console.WriteLine(string .Format(" is {0}",evenDigitsNumberDoubled));

int evenDigitsNumberDoubledSum = evenDigitsNumberDoubled.ToString().Select(d => int.Parse(d.ToString())).ToList().Sum();
Console.WriteLine(string .Format(" is {0}",evenDigitsNumberDoubledSum));

int sum = oddDigitsS + evenDigitsNumberDoubledSum;
Console.WriteLine(string.Format(" is {0}", sum));``` ```//Subtract the second digit of (i.e. 5) from 10. The number must tally with the last number in the example(5).
//If the result is 2 digits, the last digit is used to compare against the last number in the example Number.
//If the answer differs, the example number is invalid.```

I don't really understand the meaning of above steps. Please explain.

TejasJ.

• Marked as answer by Wednesday, May 14, 2014 7:40 AM
Tuesday, May 13, 2014 2:27 PM

### All replies

• I have manged to reach till .

``` long input = 800121500908;
Console.WriteLine(string .Format("[Input] is {0}",input));

string inputAsString = input.ToString();

int index = 0;
int oddDigitsS =0;
long evenDigitsNumber;
long evenDigitsNumberDoubled;
string evenDigitsString = string.Empty;

foreach (char digitChar in inputAsString)
{
index++;

if (index % 2 == 1)
{
oddDigitsS += int.Parse(digitChar.ToString());
}
else
{
evenDigitsString+= digitChar.ToString();
}
}
Console.WriteLine(string .Format(" is {0}",oddDigitsS));

evenDigitsNumber = long.Parse(evenDigitsString);

evenDigitsNumberDoubled = evenDigitsNumber * 2;
Console.WriteLine(string .Format(" is {0}",evenDigitsNumberDoubled));

int evenDigitsNumberDoubledSum = evenDigitsNumberDoubled.ToString().Select(d => int.Parse(d.ToString())).ToList().Sum();
Console.WriteLine(string .Format(" is {0}",evenDigitsNumberDoubledSum));

int sum = oddDigitsS + evenDigitsNumberDoubledSum;
Console.WriteLine(string.Format(" is {0}", sum));``` ```//Subtract the second digit of (i.e. 5) from 10. The number must tally with the last number in the example(5).
//If the result is 2 digits, the last digit is used to compare against the last number in the example Number.
//If the answer differs, the example number is invalid.```

I don't really understand the meaning of above steps. Please explain.

TejasJ.

• Marked as answer by Wednesday, May 14, 2014 7:40 AM
Tuesday, May 13, 2014 2:27 PM
• Hope this helps as start..do add exception handling and modify as needed..Welcome bk to forums after two years..

```  var input = "8001215009085".ToCharArray();
var first = input.Where((x, i) => (i % 2 == 0 && i != input.Length - 1)).Select(x => x - '0').ToArray();
var firstresult = first.Sum(x => x); // 1
Console.WriteLine(firstresult);
var second = Convert.ToInt32(String.Join("", input.Where((x, i) => (i % 2 == 1 && i != input.Length - 1)).Select(x => x - '0')));
var secondresult = second * 2; //2
Console.WriteLine(secondresult);
var third = secondresult.ToString().ToCharArray().Where((x, i) => (i == i)).Select(x => x - '0').ToArray();
var thirdresult = third.Sum(x => x);
Console.WriteLine(thirdresult);
var fourthresult = firstresult + thirdresult; //4
Console.WriteLine(fourthresult);
var result =  10 - Convert.ToInt32(fourthresult.ToString().ElementAt(1) - '0');
if (result == Convert.ToInt32(input.ElementAt(input.Length - 1) - '0'))
{
Console.WriteLine("matched");
}```

Tuesday, May 13, 2014 5:36 PM
• I have manged to reach till .

``` long input = 800121500908;
Console.WriteLine(string .Format("[Input] is {0}",input));

string inputAsString = input.ToString();

int index = 0;
int oddDigitsS =0;
long evenDigitsNumber;
long evenDigitsNumberDoubled;
string evenDigitsString = string.Empty;

foreach (char digitChar in inputAsString)
{
index++;

if (index % 2 == 1)
{
oddDigitsS += int.Parse(digitChar.ToString());
}
else
{
evenDigitsString+= digitChar.ToString();
}
}
Console.WriteLine(string .Format(" is {0}",oddDigitsS));

evenDigitsNumber = long.Parse(evenDigitsString);

evenDigitsNumberDoubled = evenDigitsNumber * 2;
Console.WriteLine(string .Format(" is {0}",evenDigitsNumberDoubled));

int evenDigitsNumberDoubledSum = evenDigitsNumberDoubled.ToString().Select(d => int.Parse(d.ToString())).ToList().Sum();
Console.WriteLine(string .Format(" is {0}",evenDigitsNumberDoubledSum));

int sum = oddDigitsS + evenDigitsNumberDoubledSum;
Console.WriteLine(string.Format(" is {0}", sum));``` ```//Subtract the second digit of (i.e. 5) from 10. The number must tally with the last number in the example(5).
//If the result is 2 digits, the last digit is used to compare against the last number in the example Number.
//If the answer differs, the example number is invalid.```

I don't really understand the meaning of above steps. Please explain.

TejasJ.

You are awesome!! Thanks a Lot!

Mr.SMP

Wednesday, May 14, 2014 7:40 AM
• TejasJ, I got the last part right on my own thanks.

All it had to do was take the second digit (5) from the answer (35) in  and subtract it from 10.

If the answer in  would be 41, the second digit would be 1 and subtracted from 10 and the answer would be 9.

I know this isnt part of the question but while im at it..

the problem you solved for me right now is integer z

```long a, xy, z, count;

a = 41061800000;
xy = 8;
z = 0;
count = 41061800000;

asdf:

if (count <= 41061803800)
{
a = count;
count = count + 10;

Console.Write(a);
Console.Write(xy);
Console.Write(z);

Console.WriteLine("");
goto asdf;
}