Answer:
Check the explanation
Explanation:
class Partioner {
public static int partition(int[] values) {
if (values == null || values.length < 1)
return 0;
// getting pivot value
int pivot = values[values.length - 1];
// pivot index
int pivot_index = values.length - 1;
// looping through values
for (int i = values.length - 2; i >= 0; i--) {
if (values[i] == pivot) {
pivot_index--;
continue;
}
// if immediate number is greater than pivot
if (values[i] > pivot) {
if (pivot_index - i == 1) {
int temp = values[i];
values[i] = pivot;
values[pivot_index] = temp;
pivot_index--;
} else {
int temp = values[i];
values[i] = values[pivot_index - 1];
values[pivot_index - 1] = temp;
temp = values[pivot_index - 1];
values[pivot_index] = temp;
values[pivot_index - 1] = pivot;
pivot_index--;
}
}
}
// returning pivot index
return pivot_index;
}
// testing the function
public static void main(String[] args) {
int values[] = { 11, 9, 2, 7, 21, 6, 10, 10, 10 };
System.out.println("pivot index : " + Partioner.partition(values));
System.out.println();
}
}
// OUTPUT
pivot index : 4
