Get minimum value in an array and then get index - arrays

Question

I want to get the minimum value in an array and then get the index of that item, in one step without writing my own loop (if I have to please let me know).
I know I can just do the
$b = ($a | Measure -Minimum).Minimum
But then I have to do
[array]::IndexOf($a, $b)
And while that is normally okay, I'm looking for a way to do it once because I'm running this MANY MANY times in a loop.
Thanks!
EDIT: One step meaning without looping through the array twice

Answer 1

Personally, I might consider a different data structure. Maybe something sorted to begin with...
This code may work for your needs:
$myArray = 5,66,4,33,2,9,9,12
$index = 0
$minIndex = 0
$minValue = [int]::MaxValue
$myArray | % { if ($minValue -gt $_) {$minValue = $_; $minIndex = $index}; $index++ }
"MinIndex $minIndex = MinValue $minValue"

Answer 2

its a problem of type, try like this:
$myArray = [int[]]5,66,4,33,2,9,9,12
$minvalue=[int]($myArray | measure -Minimum).Minimum
$myArray.IndexOf($minvalue)

Answer 3

Here are 6 different options for you...
cls
$myArray = #(5,66,4,33,2,9,9,12)
$iterations = 50000
$t = (measure-command{
foreach ($i in 1..$iterations) {
$minValue = [int]($myArray | Measure-Object -Minimum).Minimum
$minIndex = $myArray.IndexOf($minValue)
}
}).TotalSeconds
"measure-object with indexOf: $t"
$t = (measure-command{
foreach ($i in 1..$iterations) {
$index = 0
$minIndex = 0
$minValue = [int]::MaxValue
$myArray | % { if ($minValue -gt $_) {$minValue = $_; $minIndex = $index}; $index++ }
}
}).TotalSeconds
"pipeline with compare: $t"
$t = (measure-command{
foreach ($i in 1..$iterations) {
$minIndex = 0
$minValue = [int]::MaxValue
foreach ($index in 0..($myArray.count-1)) {
if ($myArray[$index] -lt $minValue) {
$minValue = $myArray[$index]
$minIndex = $index
}
}
}
}).TotalSeconds
"foreach-loop with compare: $t"
$t = (measure-command{
foreach ($i in 1..$iterations) {
$h = [System.Collections.ArrayList]::new()
foreach ($index in 0..($myArray.count-1)) {
$null = $h.add([tuple]::Create($myArray[$index], $index))
}
$h.Sort()
$minIndex = $h[0].Item2
}
}).TotalSeconds
"quicksort of a list of tuples: $t"
Add-Type -TypeDefinition #"
using System;
using System.Linq;
public static class My {
public static int indexOfMin(int[] arr){
int min = arr.Min();
return Array.IndexOf(arr, min);
}
}
"#
$t = (measure-command{
foreach ($i in 1..$iterations) {
$minIndex = [my]::indexOfMin($myArray)
}
}).TotalSeconds
"custom type and IndexOf: $t"
Add-Type #"
public static int[] indexOfMin(int[] arr){
int min = int.MaxValue;
int minIndex = 0;
for (int i = 0; i < arr.Length; i++) {
if (arr[i]<min) {
min = arr[i];
minIndex = i;
}
}
return new int[] {min, minIndex};
}
"# -name My2 -Namespace System
$t = (measure-command{
foreach ($i in 1..$iterations) {
$minValue, $minIndex = [my2]::indexOfMin($myArray)
}
}).TotalSeconds
"custom type and looping: $t"