import java.io.*;
import java.util.*;
public class QuicksortKiller implements Runnable {
final boolean ONLINE_JUDGE = System.getProperty("ONLINE_JUDGE") != null;
PrintWriter out;
@Override
public void run() {
try {
if (ONLINE_JUDGE) {
out = new PrintWriter(System.out);
} else {
out = new PrintWriter("output.txt");
}
Locale.setDefault(Locale.US);
solve();
out.close();
} catch (Throwable e) {
e.printStackTrace(System.err);
System.exit(-1);
}
}
public static void main(String[] args) {
new Thread(null, new QuicksortKiller(), "", 256 * 1024 * 1024).start();
}
//------------------------------------------------------------------------------
final int INSERTION_SORT_THRESHOLD = 47;
private void hackedSort(int[] a, int left, int right, boolean leftmost) {
int length = right - left + 1;
// Use insertion sort on tiny arrays
if (length < INSERTION_SORT_THRESHOLD) {
if (leftmost) {
for (int i = left; i <= right; i++) {
if (a[i] == Integer.MIN_VALUE) a[i] = maxNum--;
}
/*
* Traditional (without sentinel) insertion sort,
* optimized for server VM, is used in case of
* the leftmost part.
*/
for (int i = left, j = i; i < right; j = ++i) {
int ai = a[i + 1];
int pi = p[i + 1];
while (ai < a[j]) {
a[j + 1] = a[j];
p[j + 1] = p[j];
if (j-- == left) {
break;
}
}
a[j + 1] = ai;
p[j + 1] = pi;
}
} else {
for (int i = left+1; i <= right; i++) {
if (a[i] == Integer.MIN_VALUE) a[i] = maxNum--;
}
if (a[left] == Integer.MIN_VALUE) a[left] = maxNum--;
/*
* Skip the longest ascending sequence.
*/
do {
if (left >= right) {
return;
}
} while (a[++left] >= a[left - 1]);
/*
* Every element from adjoining part plays the role
* of sentinel, therefore this allows us to avoid the
* left range check on each iteration. Moreover, we use
* the more optimized algorithm, so called pair insertion
* sort, which is faster (in the context of Quicksort)
* than traditional implementation of insertion sort.
*/
for (int k = left; ++left <= right; k = ++left) {
int a1 = a[k], a2 = a[left];
int p1 = p[k], p2 = p[left];
if (a1 < a2) {
a2 = a1; a1 = a[left];
p2 = p1; p1 = p[left];
}
while (a1 < a[--k]) {
a[k + 2] = a[k];
p[k + 2] = p[k];
}
++k;
a[k + 1] = a1;
p[k + 1] = p1;
while (a2 < a[--k]) {
a[k + 1] = a[k];
p[k + 1] = p[k];
}
a[k + 1] = a2;
p[k + 1] = p2;
}
int last = a[right];
int plast = p[right];
while (last < a[--right]) {
a[right + 1] = a[right];
p[right + 1] = p[right];
}
a[right + 1] = last;
p[right + 1] = plast;
}
return;
}
// Inexpensive approximation of length / 7
int seventh = (length >> 3) + (length >> 6) + 1;
/*
* Sort five evenly spaced elements around (and including) the
* center element in the range. These elements will be used for
* pivot selection as described below. The choice for spacing
* these elements was empirically determined to work well on
* a wide variety of inputs.
*/
int e3 = (left + right) >>> 1; // The midpoint
int e2 = e3 - seventh;
int e1 = e2 - seventh;
int e4 = e3 + seventh;
int e5 = e4 + seventh;
if (a[e1] == Integer.MIN_VALUE) a[e1] = maxNum--;
if (a[e2] == Integer.MIN_VALUE) a[e2] = maxNum--;
if (a[e3] == Integer.MIN_VALUE) a[e3] = maxNum--;
if (a[e4] == Integer.MIN_VALUE) a[e4] = maxNum--;
if (a[e5] == Integer.MIN_VALUE) a[e5] = maxNum--;
// Sort these elements using insertion sort
if (a[e2] < a[e1]) {
int t = a[e2]; a[e2] = a[e1]; a[e1] = t;
int pt= p[e2]; p[e2] = p[e1]; p[e1] = pt;
}
if (a[e3] < a[e2]) {
int t = a[e3]; a[e3] = a[e2]; a[e2] = t;
int pt= p[e3]; p[e3] = p[e2]; p[e2] = pt;
if (t < a[e1]) {
a[e2] = a[e1]; a[e1] = t;
p[e2] = p[e1]; p[e1] = pt;
}
}
if (a[e4] < a[e3]) {
int t = a[e4]; a[e4] = a[e3]; a[e3] = t;
int pt= p[e4]; p[e4] = p[e3]; p[e3] = pt;
if (t < a[e2]) {
a[e3] = a[e2]; a[e2] = t;
p[e3] = p[e2]; p[e2] = pt;
if (t < a[e1]) {
a[e2] = a[e1]; a[e1] = t;
p[e2] = p[e1]; p[e1] = pt;
}
}
}
if (a[e5] < a[e4]) {
int t = a[e5]; a[e5] = a[e4]; a[e4] = t;
int pt= p[e5]; p[e5] = p[e4]; p[e4] = pt;
if (t < a[e3]) {
a[e4] = a[e3]; a[e3] = t;
p[e4] = p[e3]; p[e3] = pt;
if (t < a[e2]) {
a[e3] = a[e2]; a[e2] = t;
p[e3] = p[e2]; p[e2] = pt;
if (t < a[e1]) {
a[e2] = a[e1]; a[e1] = t;
p[e2] = p[e1]; p[e1] = pt;
}
}
}
}
// Pointers
int less = left; // The index of the first element of center part
int great = right; // The index before the first element of right part
if (a[e1] != a[e2] && a[e2] != a[e3] && a[e3] != a[e4] && a[e4] != a[e5]) {
/*
* Use the second and fourth of the five sorted elements as pivots.
* These values are inexpensive approximations of the first and
* second terciles of the array. Note that pivot1 <= pivot2.
*/
int pivot1 = a[e2]; int ppivot1 = p[e2];
int pivot2 = a[e4]; int ppivot2 = p[e4];
/*
* The first and the last elements to be sorted are moved to the
* locations formerly occupied by the pivots. When partitioning
* is complete, the pivots are swapped back into their final
* positions, and excluded from subsequent sorting.
*/
a[e2] = a[left]; p[e2] = p[left];
a[e4] = a[right]; p[e4] = p[right];
/*
* Skip elements, which are less or greater than pivot values.
*/
while (a[++less] < pivot1);
while (a[--great] > pivot2);
/*
* Partitioning:
*
* left part center part right part
* +--------------------------------------------------------------+
* | < pivot1 | pivot1 <= && <= pivot2 | ? | > pivot2 |
* +--------------------------------------------------------------+
* ^ ^ ^
* | | |
* less k great
*
* Invariants:
*
* all in (left, less) < pivot1
* pivot1 <= all in [less, k) <= pivot2
* all in (great, right) > pivot2
*
* Pointer k is the first index of ?-part.
*/
outer:
for (int k = less - 1; ++k <= great; ) {
int ak = a[k];
int pk = p[k];
if (ak < pivot1) { // Move a[k] to left part
a[k] = a[less];
p[k] = p[less];
/*
* Here and below we use "a[i] = b; i++;" instead
* of "a[i++] = b;" due to performance issue.
*/
a[less] = ak;
p[less] = pk;
++less;
} else if (ak > pivot2) { // Move a[k] to right part
while (a[great] > pivot2) {
if (great-- == k) {
break outer;
}
}
if (a[great] < pivot1) { // a[great] <= pivot2
a[k] = a[less];
p[k] = p[less];
a[less] = a[great];
p[less] = p[great];
++less;
} else { // pivot1 <= a[great] <= pivot2
a[k] = a[great];
p[k] = p[great];
}
/*
* Here and below we use "a[i] = b; i--;" instead
* of "a[i--] = b;" due to performance issue.
*/
a[great] = ak;
p[great] = pk;
--great;
}
}
// Swap pivots into their final positions
a[left] = a[less - 1]; a[less - 1] = pivot1;
p[left] = p[less - 1]; p[less - 1] = ppivot1;
a[right] = a[great + 1]; a[great + 1] = pivot2;
p[right] = p[great + 1]; p[great + 1] = ppivot2;
// Sort left and right parts recursively, excluding known pivots
hackedSort(a, left, less - 2, leftmost);
hackedSort(a, great + 2, right, false);
/*
* If center part is too large (comprises > 4/7 of the array),
* swap internal pivot values to ends.
*/
if (less < e1 && e5 < great) {
throw new RuntimeException();
}
// Sort center part recursively
hackedSort(a, less, great, false);
} else { // Partitioning with one pivot
throw new RuntimeException();
}
}
int maxNum;
int[] p;
int[] killJava7Quicksort(int n) {
maxNum = n;
p = new int[n];
int[] t = new int[n];
for (int i = 0; i < n; i++) {
p[i] = i;
t[i] = Integer.MIN_VALUE;
}
hackedSort(t, 0, n-1, true);
validate(p, n, 0, n-1);
validate(t, n, 1, n);
int[] a = new int[n];
for (int i = 0; i < n; i++) {
a[p[i]] = t[i];
}
validate(a, n, 1, n);
return a;
}
void print(int[] a, int n) {
out.println(n);
for (int i = 0; i < n; i++) {
out.print(a[i]);
if (i == n-1) out.println(); else out.print(" ");
}
}
void validate(int[] a, int n, int L, int R) {
boolean[] used = new boolean[n];
for (int x : a) {
if (x < L || R < x) {
throw new RuntimeException();
}
if (used[x - L]) {
throw new RuntimeException();
}
used[x - L] = true;
}
}
void solve() throws IOException {
long t1, t2;
int[] a;
// TODO
// 1. enter size of the array to variable n
// 2. if property ONLINE_JUDGE is not defined on your local computer it outputs array in file output.txt
// 3. don't forget to comment 'System.out.println()' and 'Arrays.sort()' calls before submit
// 4. it may not work for some values of n because there's a bug somewhere, so check if sort really works slow before submit
int n = 100000;
{
t1 = System.currentTimeMillis();
a = killJava7Quicksort(n);
t2 = System.currentTimeMillis();
System.out.println("Generation takes " + (t2-t1) + " ms");
}
print(a, n);
{
t1 = System.currentTimeMillis();
Arrays.sort(a);
t2 = System.currentTimeMillis();
System.out.println("Sort takes " + (t2-t1) + " ms");
}
System.out.println("Thank you for using Quicksort Killer");
}
}