Mega Code Archive
Combine Quick Sort Insertion Sort
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public class CombineQuickSortInsertionSort {
private long[] data;
private int len;
public CombineQuickSortInsertionSort(int max) {
data = new long[max];
len = 0;
}
public void insert(long value) {
data[len] = value;
len++;
}
public void display() {
System.out.print("Data:");
for (int j = 0; j < len; j++)
System.out.print(data[j] + " ");
System.out.println("");
}
public void quickSort() {
recQuickSort(0, len - 1);
}
public void recQuickSort(int left, int right) {
int size = right - left + 1;
if (size < 10) // insertion sort if small
insertionSort(left, right);
else // quicksort if large
{
long median = medianOf3(left, right);
int partition = partitionIt(left, right, median);
recQuickSort(left, partition - 1);
recQuickSort(partition + 1, right);
}
}
public long medianOf3(int left, int right) {
int center = (left + right) / 2;
// order left & center
if (data[left] > data[center])
swap(left, center);
// order left & right
if (data[left] > data[right])
swap(left, right);
// order center & right
if (data[center] > data[right])
swap(center, right);
swap(center, right - 1);
return data[right - 1];
}
public void swap(int d1, int d2) {
long temp = data[d1];
data[d1] = data[d2];
data[d2] = temp;
}
public int partitionIt(int left, int right, long pivot) {
int leftPtr = left; // right of first elem
int rightPtr = right - 1; // left of pivot
while (true) {
//find bigger
while (data[++leftPtr] < pivot)
;
//find smaller
while (data[--rightPtr] > pivot)
;
if (leftPtr >= rightPtr) // if pointers cross, partition done
break;
else
swap(leftPtr, rightPtr);
}
swap(leftPtr, right - 1); // restore pivot
return leftPtr; // return pivot location
}
public void insertionSort(int left, int right) {
int in, out;
// sorted on left of out
for (out = left + 1; out <= right; out++) {
long temp = data[out]; // remove marked item
in = out; // start shifts at out
// until one is smaller,
while (in > left && data[in - 1] >= temp) {
data[in] = data[in - 1]; // shift item to right
--in; // go left one position
}
data[in] = temp; // insert marked item
}
}
public static void main(String[] args) {
int maxSize = 16;
CombineQuickSortInsertionSort arr = new CombineQuickSortInsertionSort(maxSize);
for (int j = 0; j < maxSize; j++)
{
long n = (int) (java.lang.Math.random() * 99);
arr.insert(n);
}
arr.display();
arr.quickSort();
arr.display();
}
}
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