123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444 |
- //////////////////////////////////////////////////////////////////////////////
- //
- // (C) Copyright Ion Gaztanaga 2015-2016.
- // Distributed under the Boost Software License, Version 1.0.
- // (See accompanying file LICENSE_1_0.txt or copy at
- // http://www.boost.org/LICENSE_1_0.txt)
- //
- // See http://www.boost.org/libs/move for documentation.
- //
- //////////////////////////////////////////////////////////////////////////////
- #ifndef BOOST_MOVE_MERGE_HPP
- #define BOOST_MOVE_MERGE_HPP
- #include <boost/move/algo/move.hpp>
- #include <boost/move/adl_move_swap.hpp>
- #include <boost/move/algo/detail/basic_op.hpp>
- #include <boost/move/detail/iterator_traits.hpp>
- #include <boost/move/detail/destruct_n.hpp>
- #include <boost/assert.hpp>
- namespace boost {
- namespace movelib {
- // @cond
- /*
- template<typename Unsigned>
- inline Unsigned gcd(Unsigned x, Unsigned y)
- {
- if(0 == ((x &(x-1)) | (y & (y-1)))){
- return x < y ? x : y;
- }
- else{
- do
- {
- Unsigned t = x % y;
- x = y;
- y = t;
- } while (y);
- return x;
- }
- }
- */
- //Modified version from "An Optimal In-Place Array Rotation Algorithm", Ching-Kuang Shene
- template<typename Unsigned>
- Unsigned gcd(Unsigned x, Unsigned y)
- {
- if(0 == ((x &(x-1)) | (y & (y-1)))){
- return x < y ? x : y;
- }
- else{
- Unsigned z = 1;
- while((!(x&1)) & (!(y&1))){
- z <<=1, x>>=1, y>>=1;
- }
- while(x && y){
- if(!(x&1))
- x >>=1;
- else if(!(y&1))
- y >>=1;
- else if(x >=y)
- x = (x-y) >> 1;
- else
- y = (y-x) >> 1;
- }
- return z*(x+y);
- }
- }
- template<typename RandIt>
- RandIt rotate_gcd(RandIt first, RandIt middle, RandIt last)
- {
- typedef typename iterator_traits<RandIt>::size_type size_type;
- typedef typename iterator_traits<RandIt>::value_type value_type;
- if(first == middle)
- return last;
- if(middle == last)
- return first;
- const size_type middle_pos = size_type(middle - first);
- RandIt ret = last - middle_pos;
- if (middle == ret){
- boost::adl_move_swap_ranges(first, middle, middle);
- }
- else{
- const size_type length = size_type(last - first);
- for( RandIt it_i(first), it_gcd(it_i + gcd(length, middle_pos))
- ; it_i != it_gcd
- ; ++it_i){
- value_type temp(boost::move(*it_i));
- RandIt it_j = it_i;
- RandIt it_k = it_j+middle_pos;
- do{
- *it_j = boost::move(*it_k);
- it_j = it_k;
- size_type const left = size_type(last - it_j);
- it_k = left > middle_pos ? it_j + middle_pos : first + (middle_pos - left);
- } while(it_k != it_i);
- *it_j = boost::move(temp);
- }
- }
- return ret;
- }
- template <class RandIt, class T, class Compare>
- RandIt lower_bound
- (RandIt first, const RandIt last, const T& key, Compare comp)
- {
- typedef typename iterator_traits
- <RandIt>::size_type size_type;
- size_type len = size_type(last - first);
- RandIt middle;
- while (len) {
- size_type step = len >> 1;
- middle = first;
- middle += step;
- if (comp(*middle, key)) {
- first = ++middle;
- len -= step + 1;
- }
- else{
- len = step;
- }
- }
- return first;
- }
- template <class RandIt, class T, class Compare>
- RandIt upper_bound
- (RandIt first, const RandIt last, const T& key, Compare comp)
- {
- typedef typename iterator_traits
- <RandIt>::size_type size_type;
- size_type len = size_type(last - first);
- RandIt middle;
- while (len) {
- size_type step = len >> 1;
- middle = first;
- middle += step;
- if (!comp(key, *middle)) {
- first = ++middle;
- len -= step + 1;
- }
- else{
- len = step;
- }
- }
- return first;
- }
- template<class RandIt, class Compare, class Op>
- void op_merge_left( RandIt buf_first
- , RandIt first1
- , RandIt const last1
- , RandIt const last2
- , Compare comp
- , Op op)
- {
- for(RandIt first2=last1; first2 != last2; ++buf_first){
- if(first1 == last1){
- op(forward_t(), first2, last2, buf_first);
- return;
- }
- else if(comp(*first2, *first1)){
- op(first2, buf_first);
- ++first2;
- }
- else{
- op(first1, buf_first);
- ++first1;
- }
- }
- if(buf_first != first1){//In case all remaining elements are in the same place
- //(e.g. buffer is exactly the size of the second half
- //and all elements from the second half are less)
- op(forward_t(), first1, last1, buf_first);
- }
- else{
- buf_first = buf_first;
- }
- }
- // [buf_first, first1) -> buffer
- // [first1, last1) merge [last1,last2) -> [buf_first,buf_first+(last2-first1))
- // Elements from buffer are moved to [last2 - (first1-buf_first), last2)
- // Note: distance(buf_first, first1) >= distance(last1, last2), so no overlapping occurs
- template<class RandIt, class Compare>
- void merge_left
- (RandIt buf_first, RandIt first1, RandIt const last1, RandIt const last2, Compare comp)
- {
- op_merge_left(buf_first, first1, last1, last2, comp, move_op());
- }
- // [buf_first, first1) -> buffer
- // [first1, last1) merge [last1,last2) -> [buf_first,buf_first+(last2-first1))
- // Elements from buffer are swapped to [last2 - (first1-buf_first), last2)
- // Note: distance(buf_first, first1) >= distance(last1, last2), so no overlapping occurs
- template<class RandIt, class Compare>
- void swap_merge_left
- (RandIt buf_first, RandIt first1, RandIt const last1, RandIt const last2, Compare comp)
- {
- op_merge_left(buf_first, first1, last1, last2, comp, swap_op());
- }
- template<class RandIt, class Compare, class Op>
- void op_merge_right
- (RandIt const first1, RandIt last1, RandIt last2, RandIt buf_last, Compare comp, Op op)
- {
- RandIt const first2 = last1;
- while(first1 != last1){
- if(last2 == first2){
- op(backward_t(), first1, last1, buf_last);
- return;
- }
- --last2;
- --last1;
- --buf_last;
- if(comp(*last2, *last1)){
- op(last1, buf_last);
- ++last2;
- }
- else{
- op(last2, buf_last);
- ++last1;
- }
- }
- if(last2 != buf_last){ //In case all remaining elements are in the same place
- //(e.g. buffer is exactly the size of the first half
- //and all elements from the second half are less)
- op(backward_t(), first2, last2, buf_last);
- }
- }
- // [last2, buf_last) - buffer
- // [first1, last1) merge [last1,last2) -> [first1+(buf_last-last2), buf_last)
- // Note: distance[last2, buf_last) >= distance[first1, last1), so no overlapping occurs
- template<class RandIt, class Compare>
- void merge_right
- (RandIt first1, RandIt last1, RandIt last2, RandIt buf_last, Compare comp)
- {
- op_merge_right(first1, last1, last2, buf_last, comp, move_op());
- }
- // [last2, buf_last) - buffer
- // [first1, last1) merge [last1,last2) -> [first1+(buf_last-last2), buf_last)
- // Note: distance[last2, buf_last) >= distance[first1, last1), so no overlapping occurs
- template<class RandIt, class Compare>
- void swap_merge_right
- (RandIt first1, RandIt last1, RandIt last2, RandIt buf_last, Compare comp)
- {
- op_merge_right(first1, last1, last2, buf_last, comp, swap_op());
- }
- // cost: min(L1,L2)^2+max(L1,L2)
- template<class RandIt, class Compare>
- void merge_bufferless(RandIt first, RandIt middle, RandIt last, Compare comp)
- {
- if((middle - first) < (last - middle)){
- while(first != middle){
- RandIt const old_last1 = middle;
- middle = lower_bound(middle, last, *first, comp);
- first = rotate_gcd(first, old_last1, middle);
- if(middle == last){
- break;
- }
- do{
- ++first;
- } while(first != middle && !comp(*middle, *first));
- }
- }
- else{
- while(middle != last){
- RandIt p = upper_bound(first, middle, last[-1], comp);
- last = rotate_gcd(p, middle, last);
- middle = p;
- if(middle == first){
- break;
- }
- --p;
- do{
- --last;
- } while(middle != last && !comp(last[-1], *p));
- }
- }
- }
- template<class Comp>
- struct antistable
- {
- antistable(Comp &comp)
- : m_comp(comp)
- {}
- template<class U, class V>
- bool operator()(const U &u, const V & v)
- { return !m_comp(v, u); }
- private:
- antistable & operator=(const antistable &);
- Comp &m_comp;
- };
- // [r_first, r_last) are already in the right part of the destination range.
- template <class Compare, class InputIterator, class InputOutIterator, class Op>
- void op_merge_with_right_placed
- ( InputIterator first, InputIterator last
- , InputOutIterator dest_first, InputOutIterator r_first, InputOutIterator r_last
- , Compare comp, Op op)
- {
- BOOST_ASSERT((last - first) == (r_first - dest_first));
- while ( first != last ) {
- if (r_first == r_last) {
- InputOutIterator end = op(forward_t(), first, last, dest_first);
- BOOST_ASSERT(end == r_last);
- (void)end;
- return;
- }
- else if (comp(*r_first, *first)) {
- op(r_first, dest_first);
- ++r_first;
- }
- else {
- op(first, dest_first);
- ++first;
- }
- ++dest_first;
- }
- // Remaining [r_first, r_last) already in the correct place
- }
- template <class Compare, class InputIterator, class InputOutIterator>
- void swap_merge_with_right_placed
- ( InputIterator first, InputIterator last
- , InputOutIterator dest_first, InputOutIterator r_first, InputOutIterator r_last
- , Compare comp)
- {
- op_merge_with_right_placed(first, last, dest_first, r_first, r_last, comp, swap_op());
- }
- // [r_first, r_last) are already in the right part of the destination range.
- template <class Compare, class Op, class BidirIterator, class BidirOutIterator>
- void op_merge_with_left_placed
- ( BidirOutIterator const first, BidirOutIterator last, BidirOutIterator dest_last
- , BidirIterator const r_first, BidirIterator r_last
- , Compare comp, Op op)
- {
- BOOST_ASSERT((dest_last - last) == (r_last - r_first));
- while( r_first != r_last ) {
- if(first == last) {
- BidirOutIterator res = op(backward_t(), r_first, r_last, dest_last);
- BOOST_ASSERT(last == res);
- (void)res;
- return;
- }
- --r_last;
- --last;
- if(comp(*r_last, *last)){
- ++r_last;
- --dest_last;
- op(last, dest_last);
- }
- else{
- ++last;
- --dest_last;
- op(r_last, dest_last);
- }
- }
- // Remaining [first, last) already in the correct place
- }
- // @endcond
- // [r_first, r_last) are already in the right part of the destination range.
- template <class Compare, class BidirIterator, class BidirOutIterator>
- void merge_with_left_placed
- ( BidirOutIterator const first, BidirOutIterator last, BidirOutIterator dest_last
- , BidirIterator const r_first, BidirIterator r_last
- , Compare comp)
- {
- op_merge_with_left_placed(first, last, dest_last, r_first, r_last, comp, move_op());
- }
- // [r_first, r_last) are already in the right part of the destination range.
- template <class Compare, class InputIterator, class InputOutIterator>
- void merge_with_right_placed
- ( InputIterator first, InputIterator last
- , InputOutIterator dest_first, InputOutIterator r_first, InputOutIterator r_last
- , Compare comp)
- {
- op_merge_with_right_placed(first, last, dest_first, r_first, r_last, comp, move_op());
- }
- // [r_first, r_last) are already in the right part of the destination range.
- // [dest_first, r_first) is uninitialized memory
- template <class Compare, class InputIterator, class InputOutIterator>
- void uninitialized_merge_with_right_placed
- ( InputIterator first, InputIterator last
- , InputOutIterator dest_first, InputOutIterator r_first, InputOutIterator r_last
- , Compare comp)
- {
- BOOST_ASSERT((last - first) == (r_first - dest_first));
- typedef typename iterator_traits<InputOutIterator>::value_type value_type;
- InputOutIterator const original_r_first = r_first;
- destruct_n<value_type> d(&*dest_first);
- while ( first != last && dest_first != original_r_first ) {
- if (r_first == r_last) {
- for(; dest_first != original_r_first; ++dest_first, ++first){
- ::new(&*dest_first) value_type(::boost::move(*first));
- d.incr();
- }
- d.release();
- InputOutIterator end = ::boost::move(first, last, original_r_first);
- BOOST_ASSERT(end == r_last);
- (void)end;
- return;
- }
- else if (comp(*r_first, *first)) {
- ::new(&*dest_first) value_type(::boost::move(*r_first));
- d.incr();
- ++r_first;
- }
- else {
- ::new(&*dest_first) value_type(::boost::move(*first));
- d.incr();
- ++first;
- }
- ++dest_first;
- }
- d.release();
- merge_with_right_placed(first, last, original_r_first, r_first, r_last, comp);
- }
- } //namespace movelib {
- } //namespace boost {
- #endif //#define BOOST_MOVE_MERGE_HPP
|