If I have a two dimensional array as follows, is it possible to sort the array by the last element? (last element means 2, 10, 1, 5)
string[,] original = new string[4, 3] { {"apple","price1", "2"}, {"orange","price2", "10"} , {"Pineapple","price5", "1"}, {"Kiwi","price3", "5"}};
This doesn't directly answer the question, but a cleaner implementation might be something like...
public class Fruit : IComparer<Fruit>, IComparable<Fruit>
{
public Fruit(string name, double price, int quantity)
{
Name = name;
Price = price;
Quantity = quantity;
}
protected int Quantity { get; set; }
protected double Price { get; set; }
protected string Name { get; set; }
public int CompareTo(Fruit other)
{
if (Quantity < other.Quantity) return 1;
if (Quantity > other.Quantity) return -1;
return 0;
}
public override string ToString()
{
return string.Format("{0} {1} {2}", Name, Price, Quantity);
}
public int Compare(Fruit x, Fruit y)
{
if (x.Quantity > y.Quantity) return 1;
if (x.Quantity < y.Quantity) return -1;
return 0;
}
}
Then you can use the new class like this...
var fruits = new List<Fruit>
{
new Fruit("Apple", 0.30, 2),
new Fruit("Orange", 0.50, 10),
new Fruit("Pineapple", 0.35, 1),
new Fruit("Kiwi", 0.33, 5)
};
Console.WriteLine("Before sort");
foreach (var fruit in fruits)
{
Console.WriteLine(fruit.ToString());
}
fruits.Sort();
Console.WriteLine("After sort");
foreach (var fruit in fruits)
{
Console.WriteLine(fruit.ToString());
}
fruits.Reverse();
Console.WriteLine("After reverse");
foreach (var fruit in fruits)
{
Console.WriteLine(fruit.ToString());
}
Console.ReadLine();
Output:
You can do something like this
public static void Sort(string[,] original)
{
var data=new List<List<string>>();
for (int i = 0; i < original.GetLength(0); i++)
{
var m=new List<string>();
for (int j = 0; j < original.GetLength(1); j++)
{
m.Add(original[i,j]) ;
}
data.Add(m);
}
var l = data.OrderBy(x => int.Parse(x[2])).ToList();
for (int i = 0; i < original.GetLength(0); i++)
{
for (int j = 0; j < original.GetLength(1); j++)
{
original[i, j] = l[i][j];
}
}
}
It is possible, but as already pointed in the comments there are better ways to design your data structure. Anyhow, if you want to stick to your array, a possible (there are many ways to do the sorting) solution could look like this:
string[,] original = new string[4, 3]
{
{"apple","price1", "2"},
{"orange","price2", "10"} ,
{"Pineapple","price5", "1"},
{"Kiwi","price3", "5"}
};
// extract the data
var indexAndOrder = new List<Tuple<string, string, int>>();
for (var i = 0; i < original[0,0].Length - 1; i++)
{
var current = int.Parse(original[i, 2]);
indexAndOrder.Add(new Tuple<string, string, int>(original[i,0], original[i,1], current));
}
// anonymous object to sort the indices
var sortedArray = indexAndOrder
.Select (ao => new { Name = ao.Item1, Price = ao.Item2, Index = ao.Item3})
.ToList()
.OrderBy (ao => ao.Index)
//.OrderByDescending (ao => ao.Index)
.ToArray();
foreach (var item in sortedArray)
{
Console.WriteLine(string.Format("{0} - {1} - {2}", item.Index, item.Name, item.Price));
}
The output is:
1 - Pineapple - price5
2 - apple - price1
5 - Kiwi - price3
10 - orange - price2
The algorithm can always be extracted in a function and return a new sorted array.
For reference, it is also possible with a single LINQ query (yet probably not most effective):
string[,] original = new string[4, 3] { { "apple", "price1", "2" }, { "orange", "price2", "10" }, { "Pineapple", "price5", "1" }, { "Kiwi", "price3", "5" } };
var l = original.Cast<string>()
.Select((element, index) => new { element, index })
.GroupBy(x => x.index / 3)
.Select(x => new
{
Id = x.ElementAt(0).element,
Name = x.ElementAt(1).element,
Value = int.Parse(x.ElementAt(2).element)
})
.OrderBy(x => x.Value)
.Select(x => new string[] { x.Id, x.Name, x.Value.ToString() })
.ToArray();
See this question to understand it more.
static int MCompare(string[] x, string[] y)
{
return String.Compare(x[2], y[2]);
}
static void Main(string[] args)
{
string[,] original = new string[4, 3]
{
{"apple","price1", "2"},
{"orange","price2", "10"} ,
{"Pineapple","price5", "1"},
{"Kiwi","price3", "5"}
};
string[][] temp = new string[4][];
for (int i = 0; i < 4; i++)
{
temp[i] = new string[3];
for (int j = 0; j < 3; j++)
{
temp[i][j] = original[i, j];
}
}
Array.Sort<string[]>(temp, MCompare);
}
tmp is the sort result
