Initial data commit

Task/Fast-Fourier-transform/PowerShell/fast-fourier-transform.psh

@@ -0,0 +1,32 @@
+Function FFT($Arr){
+    $Len = $Arr.Count
+
+    If($Len -le 1){Return $Arr}
+
+    $Len_Over_2 = [Math]::Floor(($Len/2))
+
+    $Output  = New-Object System.Numerics.Complex[] $Len
+
+    $EvenArr = @()
+    $OddArr  = @()
+
+    For($i = 0; $i -lt $Len; $i++){
+        If($i % 2){
+            $OddArr+=$Arr[$i]
+        }Else{
+            $EvenArr+=$Arr[$i]
+        }
+    }
+
+    $Even = FFT($EvenArr)
+    $Odd  = FFT($OddArr)
+
+    For($i = 0; $i -lt $Len_Over_2; $i++){
+        $Twiddle = [System.Numerics.Complex]::Exp([System.Numerics.Complex]::ImaginaryOne*[Math]::Pi*($i*-2/$Len))*$Odd[$i]
+
+        $Output[$i]             = $Even[$i] + $Twiddle
+        $Output[$i+$Len_Over_2] = $Even[$i] - $Twiddle
+    }
+
+    Return $Output
+}