Mega Code Archive
Quicksort
<![CDATA[
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);
}
private static void recQuickSort(int[] intArray, int left, int right) {
if (right - left <= 0)
return;
else {
int pivot = intArray[right];
int partition = partitionIt(intArray, left, right, pivot);
recQuickSort(intArray, left, partition - 1);
recQuickSort(intArray, partition + 1, right);
}
}
private static int partitionIt(int[] intArray, int left, int right, int pivot) {
int leftPtr = left - 1;
int rightPtr = right;
while (true) {
while (intArray[++leftPtr] < pivot)
;
while (rightPtr > 0 && intArray[--rightPtr] > pivot)
;
if (leftPtr >= rightPtr)
break;
else
swap(intArray, leftPtr, rightPtr);
}
swap(intArray, leftPtr, right);
return leftPtr;
}
private static void swap(int[] intArray, int dex1, int dex2) {
int temp = intArray[dex1];
intArray[dex1] = intArray[dex2];
intArray[dex2] = temp;
}
}
1
9
2
8
3
7
4
6
5
1
2
3
4
5
6
7
8
9
]]>