Sparse Int Range
//http://isotopescreencapture.codeplex.com/
//The MIT License (MIT)
using System.Collections.Generic;
using System.Linq;
namespace Isotope.Collections.Ranges
{
public static partial class EnumerableUtil
{
public static IEnumerable<T> Single<T>(T item)
{
yield return item;
}
/// <summary>
/// Given a range (start,end) and a number of steps, will yield that a number for each step
/// </summary>
/// <param name="start"></param>
/// <param name="end"></param>
/// <param name="steps"></param>
/// <returns></returns>
public static IEnumerable<double> RangeSteps(double start, double end, int steps)
{
// for non-positive number of steps, yield no points
if (steps < 1)
{
yield break;
}
// for exactly 1 step, yield the start value
if (steps == 1)
{
yield return start;
yield break;
}
// for exactly 2 stesp, yield the start value, and then the end value
if (steps == 2)
{
yield return start;
yield return end;
yield break;
}
// for 3 steps or above, start yielding the segments
// notice that the start and end values are explicitly returned so that there
// is no possibility of rounding error affecting their values
int segments = steps - 1;
double total_length = end - start;
double stepsize = total_length / segments;
yield return start;
for (int i = 1; i < (steps - 1); i++)
{
double p = start + (stepsize * i);
yield return p;
}
yield return end;
}
public static IEnumerable<TGROUP> GroupByCount<T, TGROUP>(
IEnumerable<T> items,
int group_size,
System.Func<int, TGROUP> func_new_col,
System.Action<TGROUP, int, T> func_add) where TGROUP : class
{
if (items == null)
{
throw new System.ArgumentNullException("items");
}
if (group_size < 1)
{
throw new System.ArgumentOutOfRangeException("group_size");
}
if (func_new_col == null)
{
throw new System.ArgumentNullException("func_new_col");
}
if (func_add == null)
{
throw new System.ArgumentNullException("func_add");
}
int cur_group_size = 0;
TGROUP cur_group = null;
foreach (var item in items)
{
if (cur_group_size == 0)
{
if (cur_group == null)
{
cur_group = func_new_col(group_size);
}
else
{
throw new System.InvalidOperationException();
}
}
func_add(cur_group, cur_group_size, item);
cur_group_size++;
if (cur_group_size == group_size)
{
yield return cur_group;
cur_group = null;
cur_group_size = 0;
}
}
if (cur_group_size > 0)
{
if (cur_group == null)
{
throw new System.InvalidOperationException();
}
yield return cur_group;
}
}
public static IEnumerable<TGROUP> GroupByCount<T, TGROUP>(ICollection<T> items, ICollection<int> group_sizes, System.Func<int, TGROUP> func_new_col, System.Action<TGROUP, int, T> func_add)
{
if (items == null)
{
throw new System.ArgumentNullException("items");
}
if (group_sizes == null)
{
throw new System.ArgumentNullException("group_sizes");
}
if (func_new_col == null)
{
throw new System.ArgumentNullException("func_new_col");
}
if (func_add == null)
{
throw new System.ArgumentNullException("func_add");
}
int total_group_sizes = group_sizes.Sum();
if (total_group_sizes != items.Count)
{
throw new System.ArgumentException("group_sizes must account for all items");
}
int items_added = 0;
for (int group_index = 0; group_index < group_sizes.Count; group_index++)
{
int cur_group_size = group_sizes.ElementAt(group_index);
if (cur_group_size < 0)
{
throw new System.ArgumentException("group_sizes contains a negative numver");
}
var cur_group = func_new_col(cur_group_size);
for (int row_index = 0; row_index < cur_group_size; row_index++)
{
var cur_item = items.ElementAt(items_added);
func_add(cur_group, row_index, cur_item);
items_added++;
}
yield return cur_group;
}
}
public static IDictionary<K, List<V>> Bucketize<K, V>(IEnumerable<V> items, System.Func<V, K> func_get_key, IEqualityComparer<K> ieq)
{
if (items == null)
{
throw new System.ArgumentNullException("items");
}
if (func_get_key == null)
{
throw new System.ArgumentNullException("func_get_key");
}
var dic = new Dictionary<K, List<V>>(ieq);
foreach (var item in items)
{
var key = func_get_key(item);
List<V> list = null;
bool found = dic.TryGetValue(key, out list);
if (!found)
{
list = new List<V>();
dic[key] = list;
}
list.Add(item);
}
return dic;
}
public static IDictionary<K, List<V>> Bucketize<K, V>(IEnumerable<V> items, System.Func<V, K> func_get_key)
{
IEqualityComparer<K> ieq = null;
return Bucketize<K, V>(items, func_get_key, ieq);
}
public static IDictionary<K, int> Histogram<K, V>(IEnumerable<V> items, System.Func<V, K> func_get_key, IEqualityComparer<K> ieq)
{
if (items == null)
{
throw new System.ArgumentNullException("items");
}
if (func_get_key == null)
{
throw new System.ArgumentNullException("func_get_key");
}
var dic = new Dictionary<K, int>(ieq);
foreach (var item in items)
{
var key = func_get_key(item);
int old_value = 0;
bool found = dic.TryGetValue(key, out old_value);
if (!found)
{
dic[key] = 1;
}
else
{
dic[key] = old_value + 1;
}
}
return dic;
}
public static IDictionary<T, int> Histogram<T>(IEnumerable<T> items)
{
var dic = Histogram(items, i => i, null);
return dic;
}
public static List<List<T>> Chunkify<T>(IEnumerable<T> items, int chunksize)
{
var chunks = new List<List<T>>();
List<T> cur_chunk = null;
Chunkify(items, chunksize,
() =>
{
cur_chunk = new List<T>(chunksize); chunks.Add(cur_chunk);
},
item =>
{
cur_chunk.Add(item);
});
return chunks;
}
public static void Chunkify<T>(IEnumerable<T> items, int chunksize, System.Action create_chunk, System.Action<T> add_item)
{
if (items == null)
{
throw new System.ArgumentNullException("items");
}
if (chunksize < 1)
{
throw new System.ArgumentOutOfRangeException("chunksize");
}
int item_count = 0;
int curchunk_size = 0;
foreach (T item in items)
{
if ((item_count % chunksize) == 0)
{
create_chunk();
curchunk_size = 0;
}
add_item(item);
item_count++;
curchunk_size++;
}
}
}
public struct IntRange
{
public readonly int _Lower;
public readonly int _Length;
public int Lower
{
get { return this._Lower; }
}
public int Upper
{
get { return this.Lower + this.Length - 1; }
}
public int Length
{
get { return this._Length; }
}
private IntRange(int lower, int length)
{
this._Lower = lower;
this._Length = length;
if (this.Lower > this.Upper)
{
throw new System.OverflowException();
}
}
/// <summary>
/// Creates a range from the lower and upper values
/// </summary>
/// <example>
/// (0,0) -> [0]
/// (0,1) -> [0,1]
/// (0,5) -> [0,1,2,3,4,5]
/// (2,5) -> [2,3,4,5]
/// </example>
/// <param name="lower"></param>
/// <param name="upper"></param>
/// <returns></returns>
public static IntRange FromEndpoints(int lower, int upper)
{
return new IntRange(lower, upper - lower + 1);
}
/// <summary>
/// Creates a range of a single number
/// </summary>
/// <example>
/// </example><param name="value"></param>
/// <returns></returns>
public static IntRange FromInteger(int value)
{
return new IntRange(value, 1);
}
/// <summary>
/// Creates a new range from a starting value and including all the numbers following that
/// </summary>
/// <example>
/// (2,0) -> []
/// (2,1) -> [2]
/// (2,2) -> [2,3]
/// (2,3) -> [2,3,4]
/// (2,4) -> [2,3,4,5]
/// </example>
/// <param name="lower"></param>
/// <param name="length"></param>
/// <returns></returns>
public static IntRange FromLower(int lower, int length)
{
if (length < 0)
{
throw new System.ArgumentOutOfRangeException("length", "must be >= 0");
}
return new IntRange(lower, length);
}
public override string ToString()
{
var invariant_culture = System.Globalization.CultureInfo.InvariantCulture;
return string.Format(invariant_culture, "Range({0},{1})", this.Lower, this.Upper);
}
private static bool _intersects(IntRange range1, IntRange range2)
{
return ((range1.Lower <= range2.Lower) && (range1.Upper >= range2.Lower));
}
/// <summary>
/// Tests if this range interests with another
/// </summary>
/// <param name="range">the other range</param>
/// <returns>true if they intersect</returns>
public bool Intersects(IntRange range)
{
return (_intersects(this, range) || _intersects(range, this));
}
private static int Delta = 1;
private static bool _touches(IntRange range1, IntRange range2)
{
var val = (range1.Upper + Delta) == range2.Lower;
return val;
}
/// <summary>
/// Tests if this range touches another. For example (1-2) touches (3,5) but (1,2) does not touch (4,5)
/// </summary>
/// <param name="range">the other range</param>
/// <returns>true if they touch</returns>
public bool Touches(IntRange range)
{
var val = _touches(this, range) || _touches(range, this);
return val;
}
/// <summary>
/// Tests if this range contains a specific integer
/// </summary>
/// <param name="n">the integet</param>
/// <returns>true if the number is contained</returns>
public bool Contains(int n)
{
return ((this.Lower <= n) && (n <= this.Upper));
}
/// <summary>
/// Join this range with another and return a single range that contains them both. The ranges must either touch or interest.
/// for example (0,2) amd (3,7) will yield (0,7)
/// </summary>
/// <param name="range">the other range</param>
/// <returns>the merged range</returns>
public IntRange JoinWith(IntRange range)
{
if (this.Intersects(range) || this.Touches(range))
{
int new_Upper = System.Math.Max(this.Upper, range.Upper);
int new_Lower = System.Math.Min(this.Lower, range.Lower);
return IntRange.FromEndpoints(new_Lower, new_Upper);
}
else
{
throw new System.ArgumentException();
}
}
/// <summary>
/// Get each int int he range from the lower value to the upper value
/// </summary>
/// <returns>each int in the range</returns>
public IEnumerable<int> Values
{
get
{
for (int i = this.Lower; i <= this.Upper; i++)
{
yield return i;
}
}
}
}
public class SparseIntRange
{
private List<IntRange> ranges;
public SparseIntRange()
{
this.clear();
}
public IEnumerable<IntRange> Ranges
{
get
{
foreach (var range in this.ranges)
{
yield return range;
}
}
}
public IEnumerable<int> Values
{
get
{
foreach (var rng in this.Ranges)
{
foreach (int i in rng.Values)
{
yield return i;
}
}
}
}
private void clear()
{
this.ranges = new List<IntRange>();
}
public int RangeCount
{
get { return this.ranges.Count; }
}
public void Add(int n)
{
var rng = IntRange.FromInteger(n);
this.Add(rng);
}
public void AddInclusive(int lower, int upper)
{
var rng = IntRange.FromEndpoints(lower, upper);
this.Add(rng);
}
public void Add(IntRange range)
{
var left = new List<IntRange>();
var right = new List<IntRange>();
foreach (var rng in this.ranges)
{
if (range.Intersects(rng) || range.Touches(rng))
{
range = range.JoinWith(rng);
}
else if (rng.Upper < range.Lower)
{
left.Add(rng);
}
else if (range.Upper < rng.Lower)
{
right.Add(rng);
}
else
{
throw new System.InvalidOperationException("Internal Error");
}
}
this.ranges = left.Concat(EnumerableUtil.Single(range)).Concat(right).ToList();
}
public int Lower
{
get
{
if (this.ranges.Count < 1)
{
throw new System.InvalidOperationException("There are no ranges");
}
return this.ranges[0].Lower;
}
}
public int Upper
{
get
{
if (this.ranges.Count < 1)
{
throw new System.InvalidOperationException("empty");
}
return this.ranges[this.ranges.Count - 1].Upper;
}
}
public int Count
{
get
{
int length = this.ranges.Aggregate(0, (old, rng) => old + rng.Length);
return length;
}
}
public void Remove(int value)
{
var rng = IntRange.FromInteger(value);
this.Remove(rng);
}
public void RemoveInclusive(int lower, int upper)
{
var rng = IntRange.FromEndpoints(lower, upper);
this.Remove(rng);
}
public void Remove(IntRange range)
{
// if the range doesn't intersect this collection do nothing
if (!range.Intersects(IntRange.FromEndpoints(this.Lower, this.Upper)))
{
return;
}
var middle = new List<IntRange>();
foreach (var S in this.ranges)
{
if (!range.Intersects(S))
{
middle.Add(S);
continue;
}
if ((range.Lower <= S.Lower) && (range.Upper >= S.Upper))
{
// disregard S completely
continue;
}
if (range.Lower > S.Lower)
{
if (S.Lower <= (range.Lower - 1))
{
var X = IntRange.FromEndpoints(S.Lower, range.Lower - 1);
middle.Add(X);
}
}
if (range.Upper <= S.Upper)
{
if ((range.Upper + 1) <= S.Upper)
{
var X = IntRange.FromEndpoints(range.Upper + 1, S.Upper);
middle.Add(X);
}
}
else
{
throw new System.InvalidOperationException("internal error");
}
}
this.ranges = middle;
}
public IntRange? FindRangeContainingNumber(int n)
{
foreach (var rng in this.ranges)
{
if (rng.Contains(n))
{
return rng;
}
}
return null;
}
public bool Contains(int n)
{
var rng = this.FindRangeContainingNumber(n);
return rng != null ? true : false;
}
public override string ToString()
{
var sb = new System.Text.StringBuilder();
sb.AppendFormat("{0}(", this.GetType().Name);
foreach (var rng in this.ranges)
{
sb.Append(rng.ToString());
}
sb.Append(")");
return sb.ToString();
}
}
}
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