对一组同构对象用单数组表示法实现

（算法导论第十章10.3-2）
考虑到数据安全问题，多用了一个数组来处理安全问题。

#ifndef C11LEARN_SINGULARGROUPSREPRESENTISOMORPHICOBJECTS_H
#define C11LEARN_SINGULARGROUPSREPRESENTISOMORPHICOBJECTS_H
#include  <cstring>
template<typename T>
class SingularGroupsRepresentIsomorphicObjects
{
private:int capacity;char *buffer;int *array;
public:SingularGroupsRepresentIsomorphicObjects(int capacity = 50);virtual ~SingularGroupsRepresentIsomorphicObjects();SingularGroupsRepresentIsomorphicObjects(const  SingularGroupsRepresentIsomorphicObjects<T> & l);const SingularGroupsRepresentIsomorphicObjects<T>& operator=(const  SingularGroupsRepresentIsomorphicObjects<T> & l);T*allocate();void free(T*);
};
template<typename T>
SingularGroupsRepresentIsomorphicObjects<T>::SingularGroupsRepresentIsomorphicObjects(int capacity ):capacity(capacity){if(this->capacity<=0) this->capacity = 10;buffer = new char[sizeof (T)*this->capacity];array = new int[this->capacity];memset(buffer,0,sizeof (T)*this->capacity);memset(array,0,sizeof (int)*this->capacity);
}
template<typename T>
SingularGroupsRepresentIsomorphicObjects<T>::~SingularGroupsRepresentIsomorphicObjects(){if(buffer!= nullptr){delete[] array;delete [] buffer;buffer = nullptr;array = nullptr;}
}
template<typename T>
SingularGroupsRepresentIsomorphicObjects<T>::SingularGroupsRepresentIsomorphicObjects(const SingularGroupsRepresentIsomorphicObjects<T> & l){capacity = l.capacity;buffer = new char[sizeof (T)*capacity];array = new int[capacity];memcpy(buffer,l.buffer,sizeof (T)*capacity);memcpy(array,l.array,sizeof (int)*capacity);
}
template<typename T>
const SingularGroupsRepresentIsomorphicObjects<T>& SingularGroupsRepresentIsomorphicObjects<T>::operator=(const  SingularGroupsRepresentIsomorphicObjects<T> & l){if(this == &l)return*this;if(buffer!= nullptr){delete[] array;delete [] buffer;}capacity = l.capacity;buffer = new char[sizeof (T)*capacity];array = new int[capacity];memcpy(buffer,l.buffer,sizeof (T)*capacity);memcpy(array,l.array,sizeof (int)*capacity);return *this;
}
template<typename T>
T*SingularGroupsRepresentIsomorphicObjects<T>::allocate(){int index = -1;while (++index<capacity && array[index]!=0);if(index>=capacity)throw "out of space";array[index] = -1;return (T*)(buffer+index*sizeof (T));
}
template<typename T>
void SingularGroupsRepresentIsomorphicObjects<T>::free(T* t){int index = -1;while (++index<capacity && (T*)(buffer+index*sizeof (T)) != t);if(index<capacity){memset(t,0,sizeof (T));array[index] = 0;}
}
#endif //C11LEARN_SINGULARGROUPSREPRESENTISOMORPHICOBJECTS_H

测试代码

	int arr[] = {1, 4, 6, -9, 2, -5, 10, -3, -7,12};int length = sizeof(arr)/sizeof (int);SingularGroupsRepresentIsomorphicObjects<int> isomorphicObjects(10);int *arr_tmp[10];int *arr_tmp_a[10];for (int i = 0; i < 10; ++i) {arr_tmp[i] = isomorphicObjects.allocate();*arr_tmp[i] = i;}for (int i = 0; i < 10; ++i) {cout<<*arr_tmp[i]<<" ";}for (int i = 0; i < 10; i+=2) {isomorphicObjects.free(arr_tmp[i]);}cout<<endl;for (int i = 0; i < 10; ++i) {cout<<*arr_tmp[i]<<" ";}cout<<endl;SingularGroupsRepresentIsomorphicObjects<int> isomorphicObjects_a;isomorphicObjects_a = isomorphicObjects;for (int i = 0; i < 5; i+=1) {arr_tmp_a[i] = isomorphicObjects_a.allocate();*arr_tmp_a[i] = i;}for (int i = 0; i < 5; ++i) {cout<<*arr_tmp_a[i]<<" ";}cout<<endl;SingularGroupsRepresentIsomorphicObjects<int> isomorphicObjects_b(isomorphicObjects);for (int i = 0; i < 5; i+=1) {arr_tmp_a[i+5] = isomorphicObjects_b.allocate();*arr_tmp_a[i+5] = i;}for (int i = 0; i < 10; ++i) {cout<<*arr_tmp_a[i]<<" ";}