数组

// 文件摘要：通用一维数组类// 文件标识：Array1D.h// 创建日期：2010-10-28// ============================================================================#ifndef ARRAR1D_H#define ARRAR1D_H#include <cstdio>#include <iostream>using namespace std;template <class ElemType>class Array1D{public:    //构造函数，分配初始内存    Array1D(int p_capacity = INIT_SIZE):elements(0),size(0),capacity(p_capacity)    {        //采用new来分配内存        elements = new ElemType[capacity];    }    //析构函数，释放分配内存    ~Array1D()    {        if(elements != 0)        {            //采用delete来配对new            delete[] elements;        }        //避免野指针(wild pointer或者stray pointer)        elements = 0;    }    //改变数组大小    bool Resize(unsigned newCapacity);    //下标访问符号    ElemType& operator[](int pIndex);    //转换操作符，作参数时会自动转换成指针    operator ElemType *()    {        return elements;    }    //插入元素    bool Insert(ElemType item,int pIndex);    //删除元素    bool Delete(int pIndex,ElemType &delItem);    //获取容量大小    size_t GetCapacity() const    {        return capacity;    }     //获取实际大小    size_t GetSize() const    {        return size;    }    //打印数组信息    void ToString() const    {        std::cout << "数组总容量为：" << capacity << "；数组实际大小为：" << size <<endl;        for(size_t index =0; index < size; ++index)        {            if(index % 10 == 0)            {                std::cout << endl;            }            std::cout << elements[index] << "\t";        }        std::cout << endl;    }     //写数组元素到文件（可以考虑重载）    bool WriteToFile(const char *path);    //读取文件到数组（可以考虑重载）    bool ReadFromFile(const char *path);    //返回数组元素的前一个元素    //返回数组元素的后一个元素private:    static const int INIT_SIZE = 100; //首次分配大小     static const int INCR_SIZE = 10;  //重新分配增量    ElemType *elements;               //数组元素首址    size_t size;                      //数组实际大小    size_t capacity;                  //数组容量大小};template <class ElemType>inline bool Array1D<ElemType>::Resize(unsigned newCapacity){    bool result = false;    //申请新内存    ElemType *newArray = new ElemType[newCapacity];    //申请失败    if(newArray == 0)        result = false;    //取小容量    size_t min = newCapacity < capacity ? newCapacity:capacity;    for(size_t index =0 ; index < min ; ++index)    {        newArray[index] = elements[index];    }    //保存新容量    capacity = newCapacity;    //保存新大小    size = newCapacity <= size ? newCapacity : size;    //删除老数组    if(elements != 0)    {        delete[] elements;    }    //保存新数组    elements = newArray;    //返回结果    result = true;    return result;}template <class ElemType>inline ElemType& Array1D<ElemType>::operator[](int pIndex){    return elements[pIndex];}template <class ElemType>inline bool Array1D<ElemType>::Insert(ElemType item,int pIndex){    bool result = true;    //先检测大小是否足够，否则重新分配    if(size >= capacity)    {        //重新分配内存增量        if(!Resize(capacity + INCR_SIZE))        {            result = false;        }    }        //右移    for(int index = size - 1; index > pIndex ; --index)    {        elements[index + 1] = elements[index];    }    //插入位置赋值    elements[pIndex] = item;    //实际大小增一    ++size;    return result;}template <class ElemType>inline bool Array1D<ElemType>::Delete(int pIndex,ElemType &delItem){    //一种更快的删除元素的方法，只要移动一个元素(如果不关心元素的次序)    // bool result = true;    // -- size;    // delItem = elements[pIndex];    // elements[pIndex] = elements[size-1];    // return result;    bool result = true;    //保留删除值    delItem = elements[pIndex];    cout << "删除了元素:" << delItem << endl;    //左移    for(size_t index = pIndex + 1; index < size  ; ++index)    {        elements[index-1] = elements[index];    }    //实际大小减一    --size;    //返回    return result;}template <class ElemType>inline bool Array1D<ElemType>::WriteToFile(const char *path){    std::FILE* outfile = 0;    int written = 0;    //打开文件    outfile = std::fopen(path,"wb");    //打开失败    if( outfile == 0 )        return false;    //写数组    written = std::fwrite(elements,sizeof(ElemType), size, outfile);    std::fclose(outfile);    //如果写入的元素数目与实际不符，则有问题    if( written != size )        return false;    //返回成功    return true;}template <class ElemType>inline bool Array1D<ElemType>::ReadFromFile(const char *path){    std::FILE* infile = 0;    int read = 0;    //打开文件    infile = std::fopen(path, "rb");    //打开失败    if( infile == 0 )        return false;    //读取文件，返回读取数目    read = fread(elements, sizeof(ElemType),size,infile);    std::fclose(infile);    //如果读入数目不符    if( read != size )        return false;    //返回成功    return true;}#endif