' How to rank elements of an integer array based on their sorted order in VB.NET
' ------------------------------------------------------------------------------
' We will:
' 1. Print the original array
' 2. Create a copy of the array
' 3. Sort the copy
' 4. Build a map (Dictionary) from value → rank
' 5. Apply ranks back to the original order
Imports System
Imports System.Collections.Generic
Module MyModule
' ------------------------------------------------------------
' Function 1: Print the array
' ------------------------------------------------------------
' Prints the contents of an integer array in a friendly format.
Sub PrintArray(arr As Integer())
Console.WriteLine("Array: [" & String.Join(", ", arr) & "]")
End Sub
' ------------------------------------------------------------
' Function 2: Create a copy of the array
' ------------------------------------------------------------
' Returns a new array with the same elements as the input.
Function CopyArray(arr As Integer()) As Integer()
Dim copy(arr.Length - 1) As Integer
Array.Copy(arr, copy, arr.Length)
Return copy
End Function
' ------------------------------------------------------------
' Function 3: Sort the array copy
' ------------------------------------------------------------
' Sorts the given array in ascending order (in-place).
Sub SortArray(arrCopy As Integer())
Array.Sort(arrCopy)
End Sub
' ------------------------------------------------------------
' Function 4: Build a map of value → rank
' ------------------------------------------------------------
' Ranking rules:
' - Lowest value gets rank 1
' - Equal values share the same rank
' - Rank increases only when encountering a new unique value
Function BuildRankMap(sortedArr As Integer()) As Dictionary(Of Integer, Integer)
Dim map As New Dictionary(Of Integer, Integer)()
Dim rank As Integer = 1 ' First unique value gets rank 1
Dim previous As Integer = sortedArr(0) ' Track last unique value
map(previous) = rank ' Assign rank to first element
' Loop through sorted array and assign ranks
For i As Integer = 1 To sortedArr.Length - 1
' If new unique value, increase rank
If sortedArr(i) <> previous Then
rank += 1
End If
map(sortedArr(i)) = rank
previous = sortedArr(i)
Next
Return map
End Function
' ------------------------------------------------------------
' Function 5: Apply ranks to original array order
' ------------------------------------------------------------
' Builds a new array where each element is replaced by its rank.
Function ApplyRanks(original As Integer(),
map As Dictionary(Of Integer, Integer)) As Integer()
Dim ranked(original.Length - 1) As Integer
For i As Integer = 0 To original.Length - 1
ranked(i) = map(original(i)) ' Replace value with rank
Next
Return ranked
End Function
' ------------------------------------------------------------
' Main ranking function
' ------------------------------------------------------------
' Orchestrates the whole process:
' 1. Print original array
' 2. Copy array
' 3. Sort the copy
' 4. Build rank map
' 5. Apply ranks and print result
Sub RankArray(arr As Integer())
PrintArray(arr)
If arr Is Nothing OrElse arr.Length = 0 Then
Return
End If
' Step 1: Copy array
Dim arrCopy As Integer() = CopyArray(arr)
' Step 2: Sort the copy
SortArray(arrCopy)
' Step 3: Build rank map
Dim rankMap As Dictionary(Of Integer, Integer) = BuildRankMap(arrCopy)
' Step 4: Apply ranks to original order
Dim ranked As Integer() = ApplyRanks(arr, rankMap)
Console.WriteLine("Rank: [" & String.Join(", ", ranked) & "]")
End Sub
' ------------------------------------------------------------
' MAIN METHOD
' ------------------------------------------------------------
Sub Main()
Dim arr As Integer() = {33, 99, 10, 25, 47, 11, 77}
RankArray(arr)
End Sub
End Module
' run:
'
' Array: [33, 99, 10, 25, 47, 11, 77]
' Rank: [4, 7, 1, 3, 5, 2, 6]
'
