Initial data commit

Task/Quickselect-algorithm/FreeBASIC/quickselect-algorithm.basic

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+Dim Shared As Long array(9), pivote
+
+Function QuickPartition (array() As Long, izda As Long, dcha As Long, pivote As Long) As Long
+    Dim As Long pivotValue = array(pivote)
+    Swap array(pivote), array(dcha)
+    Dim As Long indice = izda
+    For i As Long = izda To dcha-1
+        If array(i) < pivotValue Then
+            Swap array(indice), array(i)
+            indice += 1
+        End If
+    Next i
+    Swap array(dcha), array(indice)
+    Return indice
+End Function
+
+Function QuickSelect(array() As Long, izda As Long, dcha As Long, k As Long) As Long
+    Do
+        If izda = dcha Then Return array(izda) : End If
+        pivote = izda
+        pivote = QuickPartition(array(), izda, dcha, pivote)
+        Select Case k
+        Case pivote
+            Return array(k)
+        Case Is < pivote
+            dcha = pivote - 1
+        Case Is > pivote
+            izda = pivote + 1
+        End Select
+    Loop
+End Function
+
+Dim As Long a = Lbound(array), b = Ubound(array)
+Print "Array desordenado:  ";
+For i As Long = a To b
+    Read array(i)
+    Print array(i);
+Next i
+Data 9, 8, 7, 6, 5, 0, 1, 2, 3, 4
+
+Print !"\n\n   Array ordenado:  ";
+For i As Long = a To b
+    Print QuickSelect(array(), a, b, i);
+Next i
+Sleep