How get range of numbers [duplicate]

This question already has answers here: Is there a C# type for representing an integer Range? (10 answers) 开发者_JS百科 Closed 8 years ago.

I have a interval of number [1, 20].

I want a method which returns me range of number available if I decide to ban range [15, 18]. My method should return me a list containing [1,15] and [18, 20]

Range object could looks like something like that

public class Range
{
     int Start {get;set;}
     int End {get;set;}
}

Any help would be appreciated.

---

What about this?

IEnumerable<int> range = Enumerable.Range(1, 20);
IEnumerable<int> banned = Enumerable.Range(15, 4);
return range.Except(banned);

The Enumerable class already has a static method which will return a range of values for you - might be simpler to just use those semantics.

---

This is one of the ways:

static void Main(string[] args)
    {
        int[] allNumbers = Enumerable.Range(1, 20).ToArray();
        GetNumbers(ref allNumbers, new int[] { 16, 17 });
    }

    private static void GetNumbers(ref int[] nums, int[]exclude)
    {
        List<int> numsToExlucde =new List<int>();
        numsToExlucde.InsertRange(0, exclude);
        nums = nums.Where(w => !numsToExlucde.Contains(w)).ToArray();
    }

---

You have four possible cases. The method could look like this (I assume that range contain integer numbers only):

public class Range
{
    public int Start { get; set; }
    public int End { get; set; }

    public IList<Range> Exclude(Range r)
    {
        if (r.Start <= Start && r.End < End)
        {
            return new List<Range>{new Range { Start = r.End + 1, End = End }};
        }
        else if (r.Start > Start && r.End >= End)
        {
            return new List<Range>{new Range { Start = Start, End = r.Start - 1 }};
        }
        else if (r.Start > Start && r.End < End)
        {
            return new List<Range>
                       {
                           new Range { Start = Start, End = r.Start - 1 },
                           new Range { Start = r.End + 1, End = End }
                       };
        }
        return new List<Range>();
    }
}

// ...

static void Main(string[] args)
{
    Range r = new Range { Start = 1, End = 20};
    var list = r.Exclude(new Range{ Start = 1, End = 2} );
}

---

This can help you remove a range from another, or from a set of ranges:

public class Range {

  public int Start { get; private set; }
  public int End { get; private set; }

  public Range(int start, int end) {
    Start = start;
    End = end;
  }

  public IEnumerable<Range> RemoveFrom(Range range) {
    return RemoveFrom(new Range[] { range });
  }

  public IEnumerable<Range> RemoveFrom(IEnumerable<Range> items) {
    foreach (Range item in items) {
      if (End >= item.Start && Start <= item.End) {
        if (item.Start <= Start) {
          yield return new Range(item.Start, Start);
        }
        if (item.End >= End) {
          yield return new Range(End, item.End);
        }
      } else {
        yield return item;
      }
    }
  }

}

Example:

Range range = new Range(1, 20);
foreach (Range r in new Range(15,18).RemoveFrom(range)) {
  Console.WriteLine("{0} - {1}", r.Start, r.End);
}

Output:

1 - 15
18 - 20

Example of removing multiple ranges from other ranges:

Range[] items = new Range[] { new Range(1, 100), new Range(200, 300) };
Range[] exclude = new Range[] { new Range(25, 75), new Range(250, 280), new Range(90, 210) };
foreach (Range r in exclude) {
  items = r.RemoveFrom(items).ToArray();
}
    foreach (Range r in items) {
  Console.WriteLine("{0} - {1}", r.Start, r.End);
}

Output:

1 - 25
75 - 90
210 - 250
280 - 300

---

You need to traverse through the banned ranges and iteratively create the valid ranges while doing so.

public List<Range> getValidRanges(Range total, List<Range> banned)
{
  List<Range> valid = new ArrayList<Range>();
  int start = total.getStartTime();
  for(Range range: banned)
   {
     valid.add(new Range(start,banned.getStart()));
     start = banned.getEnd();
   }
   valid.add(new Range(start,total.getEnd()));
   return valid;
}