我有一个范围列表，我想找出它们是否重叠。
我有以下代码。这似乎不起作用。是否有一种更简单的方法来执行此操作或有效的方法：）
事先感谢您的任何建议。
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private IList<Range> rangeList;
private void Form1_Load(object sender, EventArgs e)
{
rangeList.Add(new Range{FromNumber = 0, ToNumber = 100});
rangeList.Add(new Range { FromNumber = 101, ToNumber = 200 });
// this range should over lap and throw an exception
rangeList.Add(new Range { FromNumber = 199, ToNumber = 300 });
}
private bool RangesOverlap()
{
var bigList = new List<List<int>>();
foreach (var range in this.rangeList)
{
bigList.Add(new List<int> { range.FromNumber , range.ToNumber });
}
IEnumerable<IEnumerable<int>> lists = bigList;
return lists
.Where(c => c != null && c.Any())
.Aggregate(Enumerable.Intersect)
.ToList().Count > 0;
}
}
public class Range
{
public int FromNumber { get; set; }
public int ToNumber { get; set; }
}
首先合并数字，然后检查生成的列表按顺序排序：
rangeList
.OrderBy(p => p.FromNumber)
.Select(p => new[] { p.FromNumber, p.ToNumber })
.SelectMany(p => p)
.Aggregate((p, q) => q >= p ? q : int.MaxValue) == int.MaxValue
过去，我面临着一个挑战，我必须为用户创建的范围（整数或reals）编写验证算法。我不得不检查3件事：
- 范围是连续的
- 范围不是重叠
- 低值必须始终＆lt; =远小于高
所以我想出了以下PHP算法。
//Let's hardcode an array of integers (it can be of reals as well):
$range = array
(
array(1, 13),
array(14, 20),
array(21, 45),
array(46, 50),
array(51, 60)
);
//And the validation algorithm:
$j = 0;
$rows = sizeof($range);
$step = 1; // This indicates the step of the values.
// 1 for integers, 0.1 or 0.01 for reals
for ($x=0; $x<$rows; $x++)
for ($y=0; $y<$rows; $y++) {
if ( ($range[$x][0] <= $range[$y][0]) AND ($range[$y][0] <= $range[$x][1]) AND ($x != $y) ) {
echo "Ranges intercepting"; // replace with error handling code
break 3;
}
if ( $range[$x][0] > $range[$x][1] ) {
echo "Not valid high & low"; // replace with error handling code
break 3;
}
if ( $range[$x][0] - $range[$y][1] == $step ) {
$j++;
}
}
if ( $j != $rows - $step )
echo "Not continuous"; // replace with error handling code
我们通过范围迭代并成对比较它们。对于我们：
- 找到重叠的范围并提出错误
- 查找Start＆amp;反向终点并提出错误
如果以上都没有发生，我们计算终点的差异。该数字必须等于范围的数量减去步骤（1、0.1、0.01等）。否则我们提出了一个错误。
希望这会有所帮助！
您可以通过稍微修改rezaarabs答案来满足新要求：
rangeList
.Select(p => new[] { p.FromNumber, p.ToNumber })
.SelectMany(p => p.Distinct())
.Aggregate((p, q) => q >= p ? q : int.MaxValue) == int.MaxValue
解决此问题的解决方案就像编写自己的RangeList : IList<Range>一样简单，当指定范围与集合中的一个或多个范围重叠时，其Add()方法会引发异常。p>工作示例：
class Range
{
public int FromNumber { get; set; }
public int ToNumber { get; set; }
public bool Intersects(Range range)
{
if ( this.FromNumber <= range.ToNumber )
{
return (this.ToNumber >= range.FromNumber);
}
else if ( this.ToNumber >= range.FromNumber )
{
return (this.FromNumber <= range.ToNumber);
}
return false;
}
}
class RangeList : IList<Range>
{
private readonly IList<Range> innerList;
#region Constructors
public RangeList()
{
this.innerList = new List<Range>();
}
public RangeList(int capacity)
{
this.innerList = new List<Range>(capacity);
}
public RangeList(IEnumerable<Range> collection)
{
if ( collection == null )
throw new ArgumentNullException("collection");
var overlap = from left in collection
from right in collection.SkipWhile(right => left != right)
where left != right
select left.Intersects(right);
if ( overlap.SkipWhile(value => value == false).Any() )
throw new ArgumentOutOfRangeException("collection", "The specified collection contains overlapping ranges.");
this.innerList = new List<Range>(collection);
}
#endregion
private bool IsUniqueRange(Range range)
{
if ( range == null )
throw new ArgumentNullException("range");
return !(this.innerList.Any(range.Intersects));
}
private Range EnsureUniqueRange(Range range)
{
if ( !IsUniqueRange(range) )
{
throw new ArgumentOutOfRangeException("range", "The specified range overlaps with one or more other ranges in this collection.");
}
return range;
}
public Range this[int index]
{
get
{
return this.innerList[index];
}
set
{
this.innerList[index] = EnsureUniqueRange(value);
}
}
public void Insert(int index, Range item)
{
this.innerList.Insert(index, EnsureUniqueRange(item));
}
public void Add(Range item)
{
this.innerList.Add(EnsureUniqueRange(item));
}
#region Remaining implementation details
public int IndexOf(Range item)
{
return this.innerList.IndexOf(item);
}
public void RemoveAt(int index)
{
this.innerList.RemoveAt(index);
}
public void Clear()
{
this.innerList.Clear();
}
public bool Contains(Range item)
{
return this.innerList.Contains(item);
}
public void CopyTo(Range[] array, int arrayIndex)
{
this.innerList.CopyTo(array, arrayIndex);
}
public int Count
{
get { return this.innerList.Count; }
}
public bool IsReadOnly
{
get { return this.innerList.IsReadOnly; }
}
public bool Remove(Range item)
{
return this.innerList.Remove(item);
}
public IEnumerator<Range> GetEnumerator()
{
return this.innerList.GetEnumerator();
}
System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
{
return this.innerList.GetEnumerator();
}
#endregion
}
用法：
IList<Range> rangeList = new RangeList();
try
{
rangeList.Add(new Range { FromNumber = 12, ToNumber = 12 });
rangeList.Add(new Range { FromNumber = 13, ToNumber = 20 }); // should NOT overlap
rangeList.Add(new Range { FromNumber = 12, ToNumber = 20 }); // should overlap
}
catch ( ArgumentOutOfRangeException exception )
{
Console.WriteLine(exception.Message);
}