# Quick sort: uses an insertion sort to handle subarrays of fewer than 10 cells : Sort « Collections « Java Tutorial

```public class MainClass {
public static void main(String[] args) {
int[] intArray = { 1, 9, 2, 8, 3, 7, 4, 6, 5 };
for (int i : intArray) {
System.out.println(i);
}
quickSort(intArray);
for (int i : intArray) {
System.out.println(i);
}
}

public static void quickSort(int[] intArray) {
recQuickSort(intArray, 0, intArray.length - 1);
insertionSort(intArray, 0, intArray.length - 1);
}

public static void recQuickSort(int[] intArray, int left, int right) {
int size = right - left + 1;
if (size < 10)
insertionSort(intArray, left, right);
else {
double median = medianOf3(intArray, left, right);
int partition = partitionIt(intArray, left, right, median);
recQuickSort(intArray, left, partition - 1);
recQuickSort(intArray, partition + 1, right);
}
}

public static double medianOf3(int[] intArray, int left, int right) {
int center = (left + right) / 2;

if (intArray[left] > intArray[center])
swap(intArray, left, center);

if (intArray[left] > intArray[right])
swap(intArray, left, right);

if (intArray[center] > intArray[right])
swap(intArray, center, right);

swap(intArray, center, right - 1);
return intArray[right - 1];
}

public static void swap(int[] intArray, int dex1, int dex2) {
int temp = intArray[dex1];
intArray[dex1] = intArray[dex2];
intArray[dex2] = temp;
}

public static int partitionIt(int[] intArray, int left, int right, double pivot) {
int leftPtr = left;
int rightPtr = right - 1;
while (true) {
while (intArray[++leftPtr] < pivot)
;
while (intArray[--rightPtr] > pivot)
;
if (leftPtr >= rightPtr)
break;
else
swap(intArray, leftPtr, rightPtr);
}
swap(intArray, leftPtr, right - 1);
return leftPtr;
}

public static void insertionSort(int[] intArray, int left, int right) {
int in, out;

for (out = left + 1; out <= right; out++) {
int temp = intArray[out];
in = out;

while (in > left && intArray[in - 1] >= temp) {
intArray[in] = intArray[in - 1];
--in;
}
intArray[in] = temp;
}
}
}
```
```1
9
2
8
3
7
4
6
5
1
2
3
4
5
6
7
8
9```
 9.53.Sort 9.53.1. Bubble Sort 9.53.2. Selection Sort 9.53.3. Insertion Sort 9.53.4. Sorting Objects using insertion sort 9.53.5. Mergesort: merging two arrays into a third 9.53.6. Generic Merge Sorter with generic Comparator 9.53.7. Shellsort 9.53.8. Quicksort: simple version of quick sort 9.53.9. Quick sort with median-of-three partitioning 9.53.10. Quick sort: uses an insertion sort to handle subarrays of fewer than 10 cells