stl_algo.h

本系统采用VC开发.可实现点云数据的处理,图像缩放,生成曲面.

/*
 *
 * Copyright (c) 1994
 * Hewlett-Packard Company
 *
 * Permission to use, copy, modify, distribute and sell this software
 * and its documentation for any purpose is hereby granted without fee,
 * provided that the above copyright notice appear in all copies and
 * that both that copyright notice and this permission notice appear
 * in supporting documentation.  Hewlett-Packard Company makes no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 *
 *
 * Copyright (c) 1996
 * Silicon Graphics Computer Systems, Inc.
 *
 * Permission to use, copy, modify, distribute and sell this software
 * and its documentation for any purpose is hereby granted without fee,
 * provided that the above copyright notice appear in all copies and
 * that both that copyright notice and this permission notice appear
 * in supporting documentation.  Silicon Graphics makes no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 */

/* NOTE: This is an internal header file, included by other STL headers.
 *   You should not attempt to use it directly.
 */

#ifndef __SGI_STL_INTERNAL_ALGO_H
#define __SGI_STL_INTERNAL_ALGO_H

#include <stl_heap.h>

__STL_BEGIN_NAMESPACE

#if defined(__sgi) && !defined(__GNUC__) && (_MIPS_SIM != _MIPS_SIM_ABI32)
#pragma set woff 1209
#endif

// __median (an extension, not present in the C++ standard).

template <class _T>
inline const _T& __median(const _T& __a, const _T& __b, const _T& __c) {
  if (__a < __b)
    if (__b < __c)
      return __b;
    else if (__a < __c)
      return __c;
    else
      return __a;
  else if (__a < __c)
    return __a;
  else if (__b < __c)
    return __c;
  else
    return __b;
}

template <class _T, class _Compare>
inline const _T&
__median(const _T& __a, const _T& __b, const _T& __c, _Compare __comp) {
  if (__comp(__a, __b))
    if (__comp(__b, __c))
      return __b;
    else if (__comp(__a, __c))
      return __c;
    else
      return __a;
  else if (__comp(__a, __c))
    return __a;
  else if (__comp(__b, __c))
    return __c;
  else
    return __b;
}

// for_each.  Apply a function to every element of a range.
template <class _InputIter, class _Function>
_Function for_each(_InputIter __first, _InputIter __last, _Function __f) {
  for ( ; __first != __last; ++__first)
    __f(*__first);
  return __f;
}

// find and find_if.

template <class _InputIter, class _T>
inline _InputIter find(_InputIter __first, _InputIter __last, const _T& __val) 
{
  while (__first != __last && *__first != __val)
    ++__first;
  return __first;
}

template <class _InputIter, class _Predicate>
_InputIter find_if(_InputIter __first, _InputIter __last,
                   _Predicate __pred) {
  while (__first != __last && !__pred(*__first))
    ++__first;
  return __first;
}

// adjacent_find.

template <class _ForwardIter>
_ForwardIter adjacent_find(_ForwardIter __first, _ForwardIter __last) {
  if (__first == __last)
    return __last;
  _ForwardIter __next = __first;
  while(++__next != __last) {
    if (*__first == *__next)
      return __first;
    __first = __next;
  }
  return __last;
}

template <class _ForwardIter, class _BinaryPredicate>
_ForwardIter adjacent_find(_ForwardIter __first, _ForwardIter __last,
                           _BinaryPredicate __binary_pred) {
  if (__first == __last)
    return __last;
  _ForwardIter __next = __first;
  while(++__next != __last) {
    if (__binary_pred(*__first, *__next))
      return __first;
    __first = __next;
  }
  return __last;
}

// count and count_if.  There are two version of each, one whose return type
// type is void and one (present only if we have partial specialization)
// whose return type is iterator_traits<_InputIter>::difference_type.  The
// C++ standard only has the latter version, but the former, which was present
// in the HP STL, is retained for backward compatibility.

template <class _InputIter, class _T, class _Size>
void count(_InputIter __first, _InputIter __last, const _T& __value,
           _Size& __n) {
  for ( ; __first != __last; ++__first)
    if (*__first == __value)
      ++__n;
}

template <class _InputIter, class _Predicate, class _Size>
void count_if(_InputIter __first, _InputIter __last, _Predicate __pred,
              _Size& __n) {
  for ( ; __first != __last; ++__first)
    if (__pred(*__first))
      ++__n;
}

#ifdef __STL_CLASS_PARTIAL_SPECIALIZATION

template <class _InputIter, class _T>
typename iterator_traits<_InputIter>::difference_type
count(_InputIter __first, _InputIter __last, const _T& __value) {
  typename iterator_traits<_InputIter>::difference_type __n = 0;
  for ( ; __first != __last; ++__first)
    if (*__first == __value)
      ++__n;
  return __n;
}

template <class _InputIter, class _Predicate>
typename iterator_traits<_InputIter>::difference_type
count_if(_InputIter __first, _InputIter __last, _Predicate __pred) {
  typename iterator_traits<_InputIter>::difference_type __n = 0;
  for ( ; __first != __last; ++__first)
    if (__pred(*__first))
      ++__n;
  return __n;
}


#endif /* __STL_CLASS_PARTIAL_SPECIALIZATION */

// search.

template <class _ForwardIter1, class _ForwardIter2>
_ForwardIter1 search(_ForwardIter1 __first1, _ForwardIter1 __last1,
                     _ForwardIter2 __first2, _ForwardIter2 __last2) 
{
  // Test for empty ranges
  if (__first1 == __last1 || __first2 == __last2)
    return __first1;

  // Test for a pattern of length 1.
  _ForwardIter2 __tmp(__first2);
  ++__tmp;
  if (__tmp == __last2)
    return find(__first1, __last1, *__first2);

  // General case.

  _ForwardIter2 __p1, __p;

  __p1 = __first2; ++__p1;

  _ForwardIter1 __current = __first1;

  while (__first1 != __last1) {
    __first1 = find(__first1, __last1, *__first2);
    if (__first1 == __last1)
      return __last1;

    __p = __p1;
    __current = __first1; 
    if (++__current == __last1)
      return __last1;

    while (*__current == *__p) {
      if (++__p == __last2)
        return __first1;
      if (++__current == __last1)
        return __last1;
    }

    ++__first1;
  }
  return __first1;
}

template <class _ForwardIter1, class _ForwardIter2, class _BinaryPred>
_ForwardIter1 search(_ForwardIter1 __first1, _ForwardIter1 __last1,
                     _ForwardIter2 __first2, _ForwardIter2 __last2,
                     _BinaryPred  __predicate) 
{
  // Test for empty ranges
  if (__first1 == __last1 || __first2 == __last2)
    return __first1;

  // Test for a pattern of length 1.
  _ForwardIter2 __tmp(__first2);
  ++__tmp;
  if (__tmp == __last2)
    return find(__first1, __last1, *__first2);

  // General case.

  _ForwardIter2 __p1, __p;

  __p1 = __first2; ++__p1;

  _ForwardIter1 __current = __first1;

  while (__first1 != __last1) {
    while (__first1 != __last1) {
      if (__predicate(*__first1, *__first2))
        break;
      ++__first1;
    }
    while (__first1 != __last1 && !__predicate(*__first1, *__first2))
      ++__first1;
    if (__first1 == __last1)
      return __last1;

    __p = __p1;
    __current = __first1; 
    if (++__current == __last1) return __last1;

    while (__predicate(*__current, *__p)) {
      if (++__p == __last2)
        return __first1;
      if (++__current == __last1)
        return __last1;
    }

    ++__first1;
  }
  return __first1;
}

// search_n.  Search for __count consecutive copies of __val.

template <class _ForwardIter, class _Integer, class _T>
_ForwardIter search_n(_ForwardIter __first, _ForwardIter __last,
                      _Integer __count, const _T& __val) {
  if (__count <= 0)
    return __first;
  else {
    __first = find(__first, __last, __val);
    while (__first != __last) {
      _Integer __n = __count - 1;
      _ForwardIter __i = __first;
      ++__i;
      while (__i != __last && __n != 0 && *__i == __val) {
        ++__i;
        --__n;
      }
      if (__n == 0)
        return __first;
      else
        __first = find(__i, __last, __val);
    }
    return __last;
  }
}

template <class _ForwardIter, class _Integer, class _T, class _BinaryPred>
_ForwardIter search_n(_ForwardIter __first, _ForwardIter __last,
                      _Integer __count, const _T& __val,
                      _BinaryPred __binary_pred) {
  if (__count <= 0)
    return __first;
  else {
    while (__first != __last) {
      if (__binary_pred(*__first, __val))
        break;
      ++__first;
    }
    while (__first != __last) {
      _Integer __n = __count - 1;
      _ForwardIter __i = __first;
      ++__i;
      while (__i != __last && __n != 0 && __binary_pred(*__i, __val)) {
        ++__i;
        --__n;
      }
      if (__n == 0)
        return __first;
      else {
        while (__i != __last) {
          if (__binary_pred(*__i, __val))
            break;
          ++__i;
        }
        __first = __i;
      }
    }
    return __last;
  }
} 

// swap_ranges

template <class _ForwardIter1, class _ForwardIter2>
_ForwardIter2 swap_ranges(_ForwardIter1 __first1, _ForwardIter1 __last1,
                          _ForwardIter2 __first2) {
  for ( ; __first1 != __last1; ++__first1, ++__first2)
    iter_swap(__first1, __first2);
  return __first2;
}

// transform

template <class _InputIter, class _OutputIter, class _UnaryOperation>
_OutputIter transform(_InputIter __first, _InputIter __last,
                      _OutputIter __result, _UnaryOperation __opr) {
  for ( ; __first != __last; ++__first, ++__result)
    *__result = __opr(*__first);
  return __result;
}

template <class _InputIter1, class _InputIter2, class _OutputIter,
          class _BinaryOperation>
_OutputIter transform(_InputIter1 __first1, _InputIter1 __last1,
                      _InputIter2 __first2, _OutputIter __result,
                      _BinaryOperation __binary_op) {
  for ( ; __first1 != __last1; ++__first1, ++__first2, ++__result)
    *__result = __binary_op(*__first1, *__first2);
  return __result;
}

// replace, replace_if, replace_copy, replace_copy_if

template <class _ForwardIter, class _T>
void replace(_ForwardIter __first, _ForwardIter __last,
             const _T& __old_value, const _T& __new_value) {
  for ( ; __first != __last; ++__first)
    if (*__first == __old_value)
      *__first = __new_value;
}

template <class _ForwardIter, class _Predicate, class _T>
void replace_if(_ForwardIter __first, _ForwardIter __last,
                _Predicate __pred, const _T& __new_value) {
  for ( ; __first != __last; ++__first)
    if (__pred(*__first))
      *__first = __new_value;
}

template <class _InputIter, class _OutputIter, class _T>
_OutputIter replace_copy(_InputIter __first, _InputIter __last,
                         _OutputIter __result,
                         const _T& __old_value, const _T& __new_value) {
  for ( ; __first != __last; ++__first, ++__result)
    *__result = *__first == __old_value ? __new_value : *__first;
  return __result;
}

template <class Iterator, class _OutputIter, class _Predicate, class _T>
_OutputIter replace_copy_if(Iterator __first, Iterator __last,
                            _OutputIter __result,
                            _Predicate __pred, const _T& __new_value) {
  for ( ; __first != __last; ++__first, ++__result)
    *__result = __pred(*__first) ? __new_value : *__first;
  return __result;
}