CODEWITHSUNDEEP
c#arraysswitch-statementrange
Ishan Jain
Ishan Jain

Reputation: 8171

How can we get range of number

I want to make a range number(for example: 1-10), according to user input in C#. I have a asp text-box, button. User can enter a number in text-box which is less than 10,000. I want, when user click on button user get the range of his input value.

For Example - If user enter "35" in text-box, he get "Number Range: (31-40)".

but, I have some special condition with making range -

If enter number between -

a) 1 to 50 the length of range is 10 - for example enter number is - 49, range is (41-50).

b) 51 to 100 the length of range is 25 - for example enter number is - 78, range is (76-100).

c) 101 to 200 the length of range is 50 - for example enter number is - 135, range is (101-150).

d) 201 to 400 the length of range is 100 - for example enter number is - 245, range is (201-300).

and so on........

I used Switch Case for this but, I didn't get success in create correct logic to get this functionality.

Thanks for help...Any help will be appreciated.

Upvotes: 0

Views: 3025

Answers (5)

Ken Kin
Ken Kin

Reputation: 4703

I guess only the numbers below 101 are specialized, otherwise it seems to meet a particular formula, and one possible solution is like the following: 

public static int[] GetRagneOf(int value) {
    var x=value>0?(value-1)/50:0;

    var power=Math.Log(x, 2);
    var count=25*(int)Math.Pow(2, power);
    var start=1+25*(int)Math.Pow(2, 1+power);

    if(value<101) {
        if(value<76) {
            if(value<51) {
                count=10;
                start=1+value-(value%10);
            }
        }
        else {
            start+=count;
        }
    }

    return Enumerable.Range(start, count).ToArray();
}

Upvotes: 0

x4rf41
x4rf41

Reputation: 5337

try this, works without any if/else/switch, just good old math:

int x = yourNumber;
int maxRange = 50;
while (x > maxRange) maxRange *= 2;
int range = maxRange / 4 / 5 * 5;
int begin = ((x-1) / range * range) + 1;
int end = begin + range - 1;

begin and end are the beginning and end of your range, i think you can do the rest yourself.

Upvotes: 1

Tseng
Tseng

Reputation: 64229

Here an example of how I'd do it, since from the initial question it's not clear if the result should be a string, an array of numbers or whatever. 

class Program {
    static void Main(string[] args) {
        int[] numbers = { 49, 78, 135, 245, 0, 1, 50, 51, 100, 101, 150, 151, 200, 201, 300, 301, 400};

        foreach(var number in numbers) {
            string result = GetRange(number);
            Console.WriteLine(string.Format("Input: {0}\tResult: {1}",number, result));
        }

        Console.ReadKey();
    }

    private static string GetRange(int number) {
        if(number <= 50) {
            return RangeByQuotient(number, 10);
        } else if(number <= 100) {
            return RangeByQuotient(number, 25);
        } else if(number <= 200) {
            return RangeByQuotient(number, 50);
        } else if(number <= 400) {
            return RangeByQuotient(number, 100);
        }

        return "Invalid Range";
    }
    private static string RangeByQuotient(int number, int quotient) {
        var lower = ((number-1) / quotient) * quotient + 1;
        var upper = (((number-1) / quotient)+1) * quotient;

        return string.Format("({0}-{1})", lower, upper);
    }
}

Results in 

Input: 49       Result: (41-50)
Input: 78       Result: (76-100)
Input: 135      Result: (101-150)
Input: 245      Result: (201-300)
Input: 0        Result: (1-10)
Input: 1        Result: (1-10)
Input: 50       Result: (41-50)
Input: 51       Result: (51-75)
Input: 100      Result: (76-100)
Input: 101      Result: (101-150)
Input: 150      Result: (101-150)
Input: 151      Result: (151-200)
Input: 200      Result: (151-200)
Input: 201      Result: (201-300)
Input: 300      Result: (201-300)
Input: 301      Result: (301-400)
Input: 400      Result: (301-400)

Update: Updated to correctly handle border cases, like 50, 51. etc.

Upvotes: 0

Sriram Sakthivel
Sriram Sakthivel

Reputation: 73492

I think this is what you're looking for Enumerable.Range

int num = 35;    
if (num <= 50)
{
    int divisor = 10;
    int quotient = num / divisor;
    var result = Enumerable.Range((quotient * divisor) + 1, divisor).ToArray();
}
else if (num <= 100 )
{
    //I assume you can expand yourself
}

Upvotes: 0

Oreflow
Oreflow

Reputation: 597

one simple method would be to use if and else-if like:

if(number < 0)
{
// number below zero
}
else if(number < 10)
{
// range 0 - 9
}
else if(number < 40)
{
// range 10 - 39
}
else if(number < 200)
{
// range 40 - 199
}
else if(number < 1000)
{
// range 200 - 999
}
else
{
// range 1000 -
}

Upvotes: 1

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