array1.h

#ifndef ARRAY1_H
#define ARRAY1_H

#include <algorithm>
#include <cstring>
#include <cassert>
#include <climits>
#include <cstdlib>
#include <iostream>
#include <stdexcept>
#include <vector>

// In this file:
//   Array1<T>: a dynamic 1D array for plain-old-data (not objects)
//   WrapArray1<T>: a 1D array wrapper around an existing array (perhaps objects, perhaps data)
// For the most part std::vector operations are supported, though for the Wrap version
// note that memory is never allocated/deleted and constructor/destructors are never called
// from within the class, thus only shallow copies can be made and some operations such as
// resize() and push_back() are limited.
// Note: for the most part assertions are done with assert(), not exceptions...

// gross template hacking to determine if a type is integral or not
struct Array1True {};
struct Array1False {};
template<typename T> struct Array1IsIntegral{ typedef Array1False type; }; // default: no (specializations to yes follow)
template<> struct Array1IsIntegral<bool>{ typedef Array1True type; };
template<> struct Array1IsIntegral<char>{ typedef Array1True type; };
template<> struct Array1IsIntegral<signed char>{ typedef Array1True type; };
template<> struct Array1IsIntegral<unsigned char>{ typedef Array1True type; };
template<> struct Array1IsIntegral<short>{ typedef Array1True type; };
template<> struct Array1IsIntegral<unsigned short>{ typedef Array1True type; };
template<> struct Array1IsIntegral<int>{ typedef Array1True type; };
template<> struct Array1IsIntegral<unsigned int>{ typedef Array1True type; };
template<> struct Array1IsIntegral<long>{ typedef Array1True type; };
template<> struct Array1IsIntegral<unsigned long>{ typedef Array1True type; };
template<> struct Array1IsIntegral<long long>{ typedef Array1True type; };
template<> struct Array1IsIntegral<unsigned long long>{ typedef Array1True type; };

//============================================================================
template<typename T>
struct Array1
{
   // STL-friendly typedefs

   typedef T* iterator;
   typedef const T* const_iterator;
   typedef unsigned long size_type;
   typedef long difference_type;
   typedef T& reference;
   typedef const T& const_reference;
   typedef T value_type;
   typedef T* pointer;
   typedef const T* const_pointer;
   typedef std::reverse_iterator<iterator> reverse_iterator;
   typedef std::reverse_iterator<const_iterator> const_reverse_iterator;

   // the actual representation

   unsigned long n;
   unsigned long max_n;
   T* data;

   // STL vector's interface, with additions, but only valid when used with plain-old-data

   Array1(void)
      : n(0), max_n(0), data(0)
   {}

   // note: default initial values are zero
   Array1(unsigned long n_)
      : n(0), max_n(0), data(0)
   {
      if(n_>ULONG_MAX/sizeof(T)) throw std::bad_alloc();
      data=(T*)std::calloc(n_, sizeof(T));
      if(!data) throw std::bad_alloc();
      n=n_;
      max_n=n_;
   }

   Array1(unsigned long n_, const T& value)
      : n(0), max_n(0), data(0)
   {
      if(n_>ULONG_MAX/sizeof(T)) throw std::bad_alloc();
      data=(T*)std::calloc(n_, sizeof(T));
      if(!data) throw std::bad_alloc();
      n=n_;
      max_n=n_;
      for(unsigned long i=0; i<n; ++i) data[i]=value;
   }

   Array1(unsigned long n_, const T& value, unsigned long max_n_)
      : n(0), max_n(0), data(0)
   {
      assert(n_<=max_n_);
      if(max_n_>ULONG_MAX/sizeof(T)) throw std::bad_alloc();
      data=(T*)std::calloc(max_n_, sizeof(T));
      if(!data) throw std::bad_alloc();
      n=n_;
      max_n=max_n_;
      for(unsigned long i=0; i<n; ++i) data[i]=value;
   }

   Array1(unsigned long n_, const T* data_)
      : n(0), max_n(0), data(0)
   {
      if(n_>ULONG_MAX/sizeof(T)) throw std::bad_alloc();
      data=(T*)std::calloc(n_, sizeof(T));
      if(!data) throw std::bad_alloc();
      n=n_;
      max_n=n_;
      assert(data_);
      std::memcpy(data, data_, n*sizeof(T));
   }

   Array1(unsigned long n_, const T* data_, unsigned long max_n_)
      : n(0), max_n(0), data(0)
   {
      assert(n_<=max_n_);
      if(max_n_>ULONG_MAX/sizeof(T)) throw std::bad_alloc();
      data=(T*)std::calloc(max_n_, sizeof(T));
      if(!data) throw std::bad_alloc();
      max_n=max_n_;
      n=n_;
      assert(data_);
      std::memcpy(data, data_, n*sizeof(T));
   }

   Array1(const Array1<T> &x)
      : n(0), max_n(0), data(0)
   {
      data=(T*)std::malloc(x.n*sizeof(T));
      if(!data) throw std::bad_alloc();
      n=x.n;
      max_n=x.n;
      std::memcpy(data, x.data, n*sizeof(T));
   }

   ~Array1(void)
   {
      std::free(data);
#ifndef NDEBUG
      data=0;
      n=max_n=0;
#endif
   }

   const T& operator[](unsigned long i) const
   { return data[i]; }

   T& operator[](unsigned long i)
   { return data[i]; }

   // these are range-checked (in debug mode) versions of operator[], like at()
   const T& operator()(unsigned long i) const
   {
      assert(i<n);
      return data[i];
   }

   T& operator()(unsigned long i)
   {
      assert(i<n);
      return data[i];
   }

   Array1<T>& operator=(const Array1<T>& x)
   {
      if(max_n<x.n){
         T* new_data=(T*)std::malloc(x.n*sizeof(T));
         if(!new_data) throw std::bad_alloc();
         std::free(data);
         data=new_data;
         max_n=x.n;
      }
      n=x.n;
      std::memcpy(data, x.data, n*sizeof(T));
      return *this;
   }

   bool operator==(const Array1<T>& x) const
   {
      if(n!=x.n) return false;
      for(unsigned long i=0; i<n; ++i) if(!(data[i]==x.data[i])) return false;
      return true;
   }
 
   bool operator!=(const Array1<T>& x) const
   {
      if(n!=x.n) return true;
      for(unsigned long i=0; i<n; ++i) if(data[i]!=x.data[i]) return true;
      return false;
   }

   bool operator<(const Array1<T>& x) const
   {
      for(unsigned long i=0; i<n && i<x.n; ++i){
         if(data[i]<x[i]) return true;
         else if(x[i]<data[i]) return false;
      }
      return n<x.n;
   }

   bool operator>(const Array1<T>& x) const
   {
      for(unsigned long i=0; i<n && i<x.n; ++i){
         if(data[i]>x[i]) return true;
         else if(x[i]>data[i]) return false;
      }
      return n>x.n;
   }

   bool operator<=(const Array1<T>& x) const
   {
      for(unsigned long i=0; i<n && i<x.n; ++i){
         if(data[i]<x[i]) return true;
         else if(x[i]<data[i]) return false;
      }
      return n<=x.n;
   }

   bool operator>=(const Array1<T>& x) const
   {
      for(unsigned long i=0; i<n && i<x.n; ++i){
         if(data[i]>x[i]) return true;
         else if(x[i]>data[i]) return false;
      }
      return n>=x.n;
   }

   void add_unique(const T& value)
   {
      for(unsigned long i=0; i<n; ++i) if(data[i]==value) return;
      if(n==max_n) grow();
      data[n++]=value;
   }

   void assign(const T& value)
   { for(unsigned long i=0; i<n; ++i) data[i]=value; }

   void assign(unsigned long num, const T& value)
   { fill(num, value); } 

   // note: copydata may not alias this array's data, and this should not be
   // used when T is a full object (which defines its own copying operation)
   void assign(unsigned long num, const T* copydata)
   {
      assert(num==0 || copydata);
      if(num>max_n){
         if(num>ULONG_MAX/sizeof(T)) throw std::bad_alloc();
         std::free(data);
         data=(T*)std::malloc(num*sizeof(T));
         if(!data) throw std::bad_alloc();
         max_n=num;
      }
      n=num;
      std::memcpy(data, copydata, n*sizeof(T));
   }

   template<typename InputIterator>
   void assign(InputIterator first, InputIterator last)
   { assign_(first, last, typename Array1IsIntegral<InputIterator>::type()); }

   template<typename InputIterator>
   void assign_(InputIterator first, InputIterator last, Array1True check)
   { fill(first, last); }

   template<typename InputIterator>
   void assign_(InputIterator first, InputIterator last, Array1False check)
   {
      unsigned long i=0;
      InputIterator p=first;
      for(; p!=last; ++p, ++i){
         if(i==max_n) grow();
         data[i]=*p;
      }
      n=i;
   }

   const T& at(unsigned long i) const
   {
      assert(i<n);
      return data[i];
   }

   T& at(unsigned long i)
   {
      assert(i<n);
      return data[i];
   }

   const T& back(void) const
   { 
      assert(data && n>0);
      return data[n-1];
   }

   T& back(void)
   {
      assert(data && n>0);
      return data[n-1];
   }

   const T* begin(void) const
   { return data; }

   T* begin(void)
   { return data; }

   unsigned long capacity(void) const
   { return max_n; }

   void clear(void)
   {
      std::free(data);
      data=0;
      max_n=0;
      n=0;
   }

   bool empty(void) const
   { return n==0; }

   const T* end(void) const
   { return data+n; }

   T* end(void)
   { return data+n; }

   void erase(unsigned long index)
   {
      assert(index<n);
      for(unsigned long i=index; i<n-1; ++i)
         data[i]=data[i-1];
      pop_back();
   }

   void fill(unsigned long num, const T& value)
   {
      if(num>max_n){
         if(num>ULONG_MAX/sizeof(T)) throw std::bad_alloc();
         std::free(data);
         data=(T*)std::malloc(num*sizeof(T));
         if(!data) throw std::bad_alloc();
         max_n=num;
      }
      n=num;
      for(unsigned long i=0; i<n; ++i) data[i]=value;
   }

   const T& front(void) const
   {
      assert(n>0);
      return *data;
   }

   T& front(void)
   {
      assert(n>0);
      return *data;
   }

   void grow(void)
   {
      unsigned long new_size=(max_n*sizeof(T)<ULONG_MAX/2 ? 2*max_n+1 : ULONG_MAX/sizeof(T));
      T *new_data=(T*)std::realloc(data, new_size*sizeof(T));
      if(!new_data) throw std::bad_alloc();
      data=new_data;
      max_n=new_size;
   }

   void insert(unsigned long index, const T& entry)
   {
      assert(index<=n);
      push_back(back());
      for(unsigned long i=n-1; i>index; --i)
         data[i]=data[i-1];
      data[index]=entry;
   }

   unsigned long max_size(void) const
   { return ULONG_MAX/sizeof(T); }

   void pop_back(void)
   {
      assert(n>0);
      --n;
   }

   void push_back(const T& value)
   {
      if(n==max_n) grow();
      data[n++]=value;
   }

   reverse_iterator rbegin(void)
   { return reverse_iterator(end()); }

   const_reverse_iterator rbegin(void) const
   { return const_reverse_iterator(end()); }

   reverse_iterator rend(void)
   { return reverse_iterator(begin()); }

   const_reverse_iterator rend(void) const
   { return const_reverse_iterator(begin()); }

   void reserve(unsigned long r)
   {
      if(r>ULONG_MAX/sizeof(T)) throw std::bad_alloc();
      T *new_data=(T*)std::realloc(data, r*sizeof(T));
      if(!new_data) throw std::bad_alloc();
      data=new_data;
      max_n=r;
   }

   void resize(unsigned long n_)
   {
      if(n_>max_n) reserve(n_);
      n=n_;
   }

   void resize(unsigned long n_, const T& value)
   {
      if(n_>max_n) reserve(n_);
      if(n<n_) for(unsigned long i=n; i<n_; ++i) data[i]=value;
      n=n_;
   }

   void set_zero(void)
   { std::memset(data, 0, n*sizeof(T)); }

   unsigned long size(void) const
   { return n; }

   void swap(Array1<T>& x)
   {
      std::swap(n, x.n);
      std::swap(max_n, x.max_n);
      std::swap(data, x.data);
   }

   // resize the array to avoid wasted space, without changing contents
   // (Note: realloc, at least on some platforms, will not do the trick)
   void trim(void)
   {
      if(n==max_n) return;
      T *new_data=(T*)std::malloc(n*sizeof(T));
      if(!new_data) return;
      std::memcpy(new_data, data, n*sizeof(T));
      std::free(data);
      data=new_data;
      max_n=n;
   }
};

// some common arrays

typedef Array1<double>             Array1d;
typedef Array1<float>              Array1f;
typedef Array1<long long>          Array1ll;
typedef Array1<unsigned long long> Array1ull;
typedef Array1<int>                Array1i;
typedef Array1<unsigned int>       Array1ui;
typedef Array1<short>              Array1s;
typedef Array1<unsigned short>     Array1us;
typedef Array1<char>               Array1c;
typedef Array1<unsigned char>      Array1uc;

//============================================================================
template<typename T>
struct WrapArray1
{
   // STL-friendly typedefs

   typedef T* iterator;
   typedef const T* const_iterator;
   typedef unsigned long size_type;
   typedef long difference_type;
   typedef T& reference;
   typedef const T& const_reference;
   typedef T value_type;
   typedef T* pointer;
   typedef const T* const_pointer;
   typedef std::reverse_iterator<iterator> reverse_iterator;
   typedef std::reverse_iterator<const_iterator> const_reverse_iterator;

   // the actual representation

   unsigned long n;
   unsigned long max_n;
   T* data;

   // most of STL vector's interface, with a few changes

   WrapArray1(void)
      : n(0), max_n(0), data(0)
   {}

   WrapArray1(unsigned long n_, T* data_)
      : n(n_), max_n(n_), data(data_)
   { assert(data || max_n==0); }

   WrapArray1(unsigned long n_, T* data_, unsigned long max_n_)
      : n(n_), max_n(max_n_), data(data_)
   {
      assert(n<=max_n);
      assert(data || max_n==0);
   }

   // Allow for simple shallow copies of existing arrays
   // Note that if the underlying arrays change where their data is, the WrapArray may be screwed up

   WrapArray1(Array1<T>& a)
      : n(a.n), max_n(a.max_n), data(a.data)
   {}

   WrapArray1(std::vector<T>& a)
      : n(a.size()), max_n(a.capacity()), data(&a[0])
   {}

   void init(unsigned long n_, T* data_, unsigned long max_n_)
   {
      assert(n_<=max_n_);
      assert(data_ || max_n_==0);
      n=n_;
      max_n=max_n_;
      data=data_;
   }

   const T& operator[](unsigned long i) const
   { return data[i]; }

   T& operator[](unsigned long i)
   { return data[i]; }

   // these are range-checked (in debug mode) versions of operator[], like at()
   const T& operator()(unsigned long i) const
   {
      assert(i<n);
      return data[i];
   }

   T& operator()(unsigned long i)
   {
      assert(i<n);
      return data[i];
   }

   bool operator==(const WrapArray1<T>& x) const
   {
      if(n!=x.n) return false;
      for(unsigned long i=0; i<n; ++i) if(!(data[i]==x.data[i])) return false;
      return true;
   }
 
   bool operator!=(const WrapArray1<T>& x) const
   {
      if(n!=x.n) return true;
      for(unsigned long i=0; i<n; ++i) if(data[i]!=x.data[i]) return true;
      return false;
   }

   bool operator<(const WrapArray1<T>& x) const
   {
      for(unsigned long i=0; i<n && i<x.n; ++i){
         if(data[i]<x[i]) return true;
         else if(x[i]<data[i]) return false;
      }
      return n<x.n;
   }

   bool operator>(const WrapArray1<T>& x) const
   {
      for(unsigned long i=0; i<n && i<x.n; ++i){
         if(data[i]>x[i]) return true;
         else if(x[i]>data[i]) return false;
      }
      return n>x.n;
   }

   bool operator<=(const WrapArray1<T>& x) const
   {
      for(unsigned long i=0; i<n && i<x.n; ++i){
         if(data[i]<x[i]) return true;
         else if(x[i]<data[i]) return false;
      }
      return n<=x.n;
   }

   bool operator>=(const WrapArray1<T>& x) const
   {
      for(unsigned long i=0; i<n && i<x.n; ++i){
         if(data[i]>x[i]) return true;
         else if(x[i]>data[i]) return false;
      }
      return n>=x.n;
   }

   void add_unique(const T& value)
   {
      for(unsigned long i=0; i<n; ++i) if(data[i]==value) return;
      assert(n<max_n);
      data[n++]=value;
   }

   void assign(const T& value)
   { for(unsigned long i=0; i<n; ++i) data[i]=value; }

   void assign(unsigned long num, const T& value)
   { fill(num, value); } 

   // note: copydata may not alias this array's data, and this should not be
   // used when T is a full object (which defines its own copying operation)
   void assign(unsigned long num, const T* copydata)
   {
      assert(num==0 || copydata);
      assert(num<=max_n);
      n=num;
      std::memcpy(data, copydata, n*sizeof(T));
   }

   template<typename InputIterator>
   void assign(InputIterator first, InputIterator last)
   { assign_(first, last, typename Array1IsIntegral<InputIterator>::type()); }

   template<typename InputIterator>
   void assign_(InputIterator first, InputIterator last, Array1True check)
   { fill(first, last); }

   template<typename InputIterator>
   void assign_(InputIterator first, InputIterator last, Array1False check)
   {
      unsigned long i=0;
      InputIterator p=first;
      for(; p!=last; ++p, ++i){
         assert(i<max_n);
         data[i]=*p;
      }
      n=i;
   }

   const T& at(unsigned long i) const
   {
      assert(i<n);
      return data[i];
   }

   T& at(unsigned long i)
   {
      assert(i<n);
      return data[i];
   }

   const T& back(void) const
   { 
      assert(data && n>0);
      return data[n-1];
   }

   T& back(void)
   {
      assert(data && n>0);
      return data[n-1];
   }

   const T* begin(void) const
   { return data; }

   T* begin(void)
   { return data; }

   unsigned long capacity(void) const
   { return max_n; }

   void clear(void)
   { n=0; }

   bool empty(void) const
   { return n==0; }

   const T* end(void) const
   { return data+n; }

   T* end(void)
   { return data+n; }

   void erase(unsigned long index)
   {
      assert(index<n);
      for(unsigned long i=index; i<n-1; ++i)
         data[i]=data[i-1];
      pop_back();
   }

   void fill(unsigned long num, const T& value)
   {
      assert(num<=max_n);
      n=num;
      for(unsigned long i=0; i<n; ++i) data[i]=value;
   }

   const T& front(void) const
   {
      assert(n>0);
      return *data;
   }

   T& front(void)
   {
      assert(n>0);
      return *data;
   }

   void insert(unsigned long index, const T& entry)
   {
      assert(index<=n);
      push_back(back());
      for(unsigned long i=n-1; i>index; --i)
         data[i]=data[i-1];
      data[index]=entry;
   }

   unsigned long max_size(void) const
   { return max_n; }

   void pop_back(void)
   {
      assert(n>0);
      --n;
   }

   void push_back(const T& value)
   {
      assert(n<max_n);
      data[n++]=value;
   }

   reverse_iterator rbegin(void)
   { return reverse_iterator(end()); }

   const_reverse_iterator rbegin(void) const
   { return const_reverse_iterator(end()); }

   reverse_iterator rend(void)
   { return reverse_iterator(begin()); }

   const_reverse_iterator rend(void) const
   { return const_reverse_iterator(begin()); }

   void reserve(unsigned long r)
   { assert(r<=max_n); }

   void resize(unsigned long n_)
   {
      assert(n_<=max_n);
      n=n_;
   }

   void resize(unsigned long n_, const T& value)
   {
      assert(n_<=max_n);
      if(n<n_) for(unsigned long i=n; i<n_; ++i) data[i]=value;
      n=n_;
   }

   // note: shouldn't be used when T is a full object (setting to zero may not make sense)
   void set_zero(void)
   { std::memset(data, 0, n*sizeof(T)); }

   unsigned long size(void) const
   { return n; }

   void swap(WrapArray1<T>& x)
   {
      std::swap(n, x.n);
      std::swap(max_n, x.max_n);
      std::swap(data, x.data);
   }
};

// some common arrays

typedef WrapArray1<double>             WrapArray1d;
typedef WrapArray1<float>              WrapArray1f;
typedef WrapArray1<long long>          WrapArray1ll;
typedef WrapArray1<unsigned long long> WrapArray1ull;
typedef WrapArray1<int>                WrapArray1i;
typedef WrapArray1<unsigned int>       WrapArray1ui;
typedef WrapArray1<short>              WrapArray1s;
typedef WrapArray1<unsigned short>     WrapArray1us;
typedef WrapArray1<char>               WrapArray1c;
typedef WrapArray1<unsigned char>      WrapArray1uc;

#endif