【发布时间】：2013-11-27 05:30:08
【问题描述】：
我必须使用 int 复制向量类并重载一堆运算符。每次我尝试使用 +、- 或 / 运算符时，我都会收到运行时错误，提示分配大小无效：4294967295 字节。也欢迎任何关于如何改进我的代码的反馈。
我的代码： myArray.h
#include<iostream>
using namespace std;
class myArray{
private:
int *A;
int lenght;
int maxSize;
public:
myArray(){lenght = 0; maxSize = 0; A = new int[maxSize];}
myArray(int s){maxSize = s; lenght = 0; A = new int[maxSize];}
myArray(const myArray &M);
~myArray(){delete[] A;}
const int getMaxSize(){return maxSize;}
const int getLenght(){return lenght;}
const myArray& operator +(const myArray& A);
const myArray& operator -(const myArray A);
const int operator *(const myArray& A);
const myArray& operator /(const myArray A);
const myArray& operator +(int A);
const myArray& operator -(int A);
const int operator *(int A);
const myArray operator /(int A);
const myArray operator ++();
const myArray operator ++(int);
const myArray operator --();
const myArray operator --(int);
myArray operator -();
int operator [](int ind) const;
myArray& operator =(const myArray& rho);
void push(int n);
int pop();
void insert(int n, int pos);
int remove(int pos);
void resize(int newSize);
};
myException.h
#include<iostream>
#include<exception>
#include<string>
using namespace std;
class myException: public exception
{
private:
int code;
string reason;
public:
myException(){code = 0; reason = "Unknown";}
myException(int c, string r){code = c; reason = r;}
friend ostream& operator <<(ostream& outputStream, const myException A);
};
ostream& operator <<(ostream& outputStream, const myException A)
{
outputStream << "Code: " << A.code << " Reason: " << A.reason << endl;
return outputStream;
}
myArray.cpp
#ifndef MYARRAY_H
#define MYARRAY_H
#include "myArray.h"
#include "myException.h"
//Copy contructor
myArray::myArray(const myArray &M)
{
maxSize = M.maxSize;
lenght = M.lenght;
A = new int[maxSize];
for(int i = 0; i < M.lenght; i++)
A[i] = M.A[i];
}
//Adds the elements of the array with each other and returns the result
const myArray& myArray::operator +(const myArray& secondArray)
{
try
{
if(lenght != secondArray.lenght)
throw myException(10, "Different sizes!");
myArray result(secondArray);
for(int i = 0; i < lenght;i++)
result.A[i] = A[i] + secondArray.A[i];
return result;
}
catch(myException& e)
{
cout << e;
}
}
//Subtracts the elements of the array with each other and returns the result
const myArray& myArray::operator -(const myArray secondArray)
{
try
{
if(lenght != secondArray.lenght)
throw myException(10, "Different sizes!");
myArray result(secondArray);
for(int i = 0; i < lenght;i++)
result.A[i] = this->A[i] - secondArray.A[i];
return result;
}
catch(myException& e)
{
cout << e;
}
}
//Gets the dot product of 2 vectors
const int myArray::operator *(const myArray& secondArray)
{
try
{
if(lenght != secondArray.lenght)
throw myException(10, "Different sizes!");
int result = 0;
for(int i = 0; i < lenght;i++)
result += this->A[i] * secondArray.A[i];
return result;
}
catch(myException& e)
{
cout << e;
}
}
//Divides the elements of the array with each other and returns the result
const myArray& myArray::operator /(const myArray secondArray)
{
try
{
if(lenght != secondArray.lenght)
throw myException(10, "Different sizes!");
myArray result(secondArray);
for(int i = 0; i < lenght;i++)
result.A[i] = this->A[i] / secondArray.A[i];
return result;
}
catch(myException& e)
{
cout << e;
}
}
//Adds the elements of the array with an int and returns the result
const myArray& myArray::operator +(int A)
{
myArray result(*this);
for(int i = 0; i < lenght;i++)
result = this->A[i] + A;
return result;
}
//Subtracts the elements of the array with an int and returns the result
const myArray& myArray::operator -(int A)
{
myArray result(*this);
for(int i = 0; i < lenght;i++)
result = this->A[i] - A;
return result;
}
//Gets the dot product of a vector multiplied by an int
const int myArray::operator *(int A)
{
int result = 0;
for(int i = 0; i < lenght;i++)
result += this->A[i] * A;
return result;
}
//Divides the elements of the array with an int and returns the result
const myArray myArray::operator /(int A)
{
myArray result(*this);
for(int i = 0; i < lenght;i++)
result = this->A[i] / A;
return result;
}
//increments every element in the array by 1(Pre-increment)
const myArray myArray::operator ++()
{
for(int i = 0; i < lenght; i++)
++A[i];
return *this;
}
//increments every element in the array by 1(Post-increment)
const myArray myArray::operator ++(int)
{
myArray temp(maxSize);
for(int i = 0; i < lenght; i++)
temp.A[i] = A[i]++;
return temp;
}
//decrements every element in the array by 1(Pre-decrement)
const myArray myArray::operator --()
{
for(int i = 0; i < lenght; i++)
--A[i];
return *this;
}
//decrements every element in the array by 1(Post-decrement)
const myArray myArray::operator --(int)
{
myArray temp(maxSize);
for(int i = 0; i < lenght; i++)
temp.A[i] = A[i]--;
return temp;
}
//Makes every element in the array negative
myArray myArray::operator -()
{
for(int i = 0; i < lenght; i++)
A[i] = -A[i];
return *this;
}
//returns the number in the array using []
int myArray::operator [](int ind) const
{
try
{
if(ind > lenght)
throw myException(60, "Array index out of bounds");
return A[ind];
}
catch(myException& e)
{
cout << e;
}
}
//Assignment operator
myArray& myArray::operator=(const myArray& B)
{
delete [] A;
A = new int[B.maxSize];
lenght = B.lenght;
maxSize = B.maxSize;
for(int i = 0; i < B.lenght; i++)
{
A[i] = B.A[i];
}
return (*this);
}
//pushes the value inserted to the next available spot in the array
void myArray::push(int n)
{
try
{
if(lenght == maxSize)
throw myException(30, "Not enough space");
if(lenght == 0)
{
A[0] = n;
lenght++;
}
else
{
for(int i = 0; i < lenght; i++)
{
if(i+1 == lenght)
{
A[i+1] = n;
lenght++;
break;
}
}
}
}
catch(myException& e)
{
cout << e;
}
}
//Removes the last element in the array and returns it
int myArray::pop()
{
try
{
if(lenght <= 0)
throw myException(60, "Array index out of bounds");
int temp = A[lenght - 1];
A[lenght - 1] = NULL;
lenght--;
return temp;
}
catch(myException& e)
{
cout << e;
}
}
inserts an element at the specified position
void myArray::insert(int n, int pos)
{
try
{
if(pos > lenght)
throw myException(60, "Array index out of bounds");
for(int i = 0; i <= lenght; i++)
{
if(i == pos)
{
A[i-1] = n;
}
}
}
catch(myException& e)
{
cout << e;
}
}
//removes an element at a specified position an returns the value.
int myArray::remove(int pos)
{
try
{
if(pos < 0 || (pos > lenght -1))
throw myException(50, "Invalid Position");
int temp = A[pos];
A[pos] = NULL;
for(int i = pos; i < lenght; i++)
{
A[i] = A[i+1];
}
return temp;
}
catch(myException& e)
{
cout << e;
}
}
//Re sizes the entire array
void myArray::resize(int newSize)
{
int *B;
B = new int[newSize];
maxSize = newSize;
for(int i = 0; i < lenght; i++)
B[i] = A[i];
delete[] A;
A = B;
}
#endif
这只是一个用于测试 myArray 类上所有内容的虚拟 main
main.cpp
#include "myArray.h"
int main()
{
int num;
myArray vector1;
myArray vector2(5);
myArray vector3;
vector1.resize(5);
//cout << "Max Size: " << vector1.getMaxSize() << endl;
for(int i = 0; i < 4; i++)
{
cin >> num;
vector1.push(num);
}
for(int i = 0; i < 4; i++)
{
cin >> num;
vector2.push(num);
}
vector3 = vector1 + vector2;
for(int i = 0; i < 4; i++)
cout << vector3.pop() << endl;
}
【问题讨论】：
-
有趣。您有一个名为
A的成员变量，并且您将函数参数命名为A。面试失败。 -
你不会喜欢这个建议，但我会很痛苦地对你说实话。你应该重新开始。您已经编写了很多代码，但您清楚地了解的很少。重新开始，不要只是编写代码，通过调试器运行它并观察它的作用。花时间让你的代码可读且有意义。并就您不确定的个别项目提出个别问题。此外，当您覆盖指针
A = new [maxSize]时，前一个值不会自动取消分配。这称为内存泄漏。你有它。另外：“长度”。
标签： c++ arrays pointers vector operator-overloading