void quicksort(int * arr, int begin, int end)
{
if (end - begin < 50)
{
insertionSort(arr, begin, end);
return;
}
int pivot = selectPivot(arr, begin, end-1);
int l = begin;
int u = end - 2;
while (1)
{
while (arr[++l] < pivot);
while (arr[--u] > pivot);
if (l < u)
swap(arr[l], arr[u]);
else
break;
}
swap(arr[l], arr[end - 1]);
quicksort(arr, begin, l);
quicksort(arr, l, end);
}
unsigned int findMinimumKSmartPivot(unsigned long* data, int length, unsigned int k) {
int pos = 0;
unsigned long * array = data;
int len = length;
int count = 0;
while(1) {
count ++;
unsigned long pivot = selectPivot(array, len);
//printf("pivot is %lu, len is %d\n", pivot, len);
int posT = partialQuickSortByPivotValue(array, len, pivot);
//printf("posT is %d\n", posT);
//printArray(array, len);
if(pos+posT+1 == k) {
break;
} else if (pos+posT+1 < k) {
pos += posT+1;
array += posT+1;
len = len - posT - 1;
} else {
len = posT;
}
}
return data[k-1];
}
void quicksort (float* arr, int size)
{
if (size <= 1) return;
else{
int pivot = selectPivot (arr, size);
swp (arr[size-1], arr[pivot]);
pivot = size-1;
// put all values less than the pivot value after the pivot
for (int i=0; i < pivot;){
if ( (arr[i] < arr[pivot]) ){
swp (arr[i], arr[pivot-1]);
swp (arr[pivot-1], arr[pivot]);
pivot--;
}
else{
i++;
}
}
quicksort (arr, pivot);
quicksort (arr+pivot, size-pivot);
}
}
