darray

#pragma once

#include <initializer_list>

template<class T>
class DArray
{
public:
  size_t size = 0;
  size_t length = 0;
  T *d{};

  DArray<T>() {}

  DArray<T>(std::initializer_list<T> &ini)
  {
    assert(!d);
    if(!ini.size()) return;
    prefill(ini.size());
    for(size_t i = 0; i < length; i++)
      d[i] = *(ini.begin()+i);
  }

  void expand(size_t nsize)
  {
    assert(nsize);
    if(nsize <= size) return;
    size = nsize;
    if(!d) d = malloc(sizeof(T)*size);
    else d = realloc(d,sizeof(T)*size);
  }

  void prefill(size_t nsize)
  {
    assert(nsize > length);
    if(nsize < size) expand(nsize);
    length = nsize;
  }

  T& append(T &v)
  { 
    assert(d);
    if(length == size)
    {
      size *= 2;
      d = realloc(v,sizeof(T)*size);
    }
    d[length++] = v;
  }

  void remove(size_t i)
  {
    assert(i < length);
    for(size_t j = i; j < length-1; j++)
      d[j] = j+1;
    length--;
  }

  DArray<T>& operator=(std::initializer_list<T> &ini)
  {
    assert(!d);
    if(!ini.size()) return;
    prefill(ini.size());
    for(size_t i = 0; i < length; i++)
      d[i] = *(ini.begin()+i);
  }

  T& operator[](size_t i) {
    assert(i < length);
    return d[i];
  };

  void cleanup()
  {
    if(d) free(d);
    d = 0;
    size = 0;
    length = 0;
  }
};