运算符重载，计算后的结果乱码

[sunnyheyun]

#include <iostream> //如下为简单的运算符重载代码，但运行后，不能正常显示结果。

using namespace std;

class Complex
{
    private:
        double  real;
        double  imag;
    public:
        Complex(double real=0.0, double imag=0.0)
        {
            real = real;
            imag = imag;
        }
        Complex operator+(Complex B);
        Complex operator-();
        Complex operator-(Complex B);

        void display();
};

Complex Complex::operator+(Complex B)
{
    return  Complex(real+B.real, imag+B.imag);
}

Complex Complex::operator-()
{
    return  Complex(-real, -imag);
}

Complex Complex::operator-(Complex B)
{
    return  Complex(real-B.real, imag-B.imag);
}

void Complex::display()
{
    cout << "NO is :" << "(" << real << "," << imag << ")" << endl;
}

int main(void)
{
    Complex A(0.0, 0.1);
    A.display();

    Complex B(1.1, 2.2);
    B.display();

    Complex C;
    C = A + B;
    C.display();

    return  0;
}

运行后显示如下：

NO is :(1.86948e-307,1.86965e-307)
NO is :(6.13927e+45,1.16621e+257)
NO is :(4.98277e-315,0)

Process returned 0 (0x0) execution time : 0.016 s
Press any key to continue.

[高性能架构探索]

有可能你没有重载“=”操作符

[weixiaoshashou]

怎么我运行的不是这样?

[高性能架构探索]

 Complex(double real=0.0, double imag=0.0)
        {
            this->real = real;
            this->imag = imag;
        }

构造函数的形参不能跟数据成员名字相同，若相同，必须使用this->

[高性能架构探索]

楼主，按照我上面的，运行一切正常

[高性能架构探索]

建议 + -等的参数命名为const Complex &,这样可以减少复制...

[chen_wenyue]

class Complex
{
private:
double m_nReal;
double m_nImag;
public:
Complex(double real=0.0, double imag=0.0)
{
m_nReal = real;
m_nImag = imag;
}
Complex operator+(Complex B);
Complex operator-();
Complex operator-(Complex B);

void display();
};

Complex Complex::operator+(Complex B)
{
return Complex(m_nReal+B.m_nReal, m_nImag+B.m_nImag);
}

Complex Complex::operator-()
{
return Complex(-m_nReal, -m_nImag);
}

Complex Complex::operator-(Complex B)
{
return Complex(m_nReal-B.m_nReal, m_nImag-B.m_nImag);
}

void Complex::display()
{
cout << "NO is :" << "(" << m_nReal << "," << m_nImag << ")" << endl;
}

给你改了一下，你的错误在于把形参跟成员变量定义成同名了，呵呵。。。。这样你在赋值时就错了。

[chen_wenyue]

void fun()
{
// 代码怎么发才是对的？？？郁闷。。。
}

[chen_wenyue]

class Complex
{
    private:
        double  m_nReal;
        double  m_nImag;
    public:
        Complex(double real=0.0, double imag=0.0)
        {
            m_nReal = real;   // 形参跟成员变量不能重名
            m_nImag = imag;
        }
        Complex operator+(Complex B);
        Complex operator-();
        Complex operator-(Complex B);

        void display();
};

Complex Complex::operator+(Complex B)
{
    return  Complex(m_nReal+B.m_nReal, m_nImag+B.m_nImag);
}

Complex Complex::operator-()
{
    return  Complex(-m_nReal, -m_nImag);
}

Complex Complex::operator-(Complex B)
{
    return  Complex(m_nReal-B.m_nReal, m_nImag-B.m_nImag);
}

void Complex::display()
{
    cout << "NO is :" << "(" << m_nReal << "," << m_nImag << ")" << endl;
}

[sunnyheyun]

谢谢各位的回答！

[sunnyheyun]

#include <iostream>
using namespace std;
#include <cv.h>
#include <highgui.h>
#include <math.h>
#pragma comment(lib,"highgui.lib")
#pragma comment(lib,"cv.lib") 
#pragma comment(lib,"cvaux.lib") 
#pragma comment(lib,"cxcore.lib") 

//全局变量声明
int HistogramBins = 256;
float HistogramRange1[2]={0,255};
float *HistogramRange[1]={&HistogramRange1[0]};
typedef
enum {back,object} entropy_state; //图像最终标记为背景、目标两块
double  cvCalculation(IplImage *pImg, int n, entropy_state state);
double  sort(double res[], int n);
int main(int argc, char *argv[])
{
 int i=0;
 int  total = 0;
 double x=0.0;
 double percentage[256] = {0.0};
 double res[256] = {0.0};
 IplImage *src = cvLoadImage(argv[1], 0);  //载入图像
 IplImage* dst = cvCreateImage(cvGetSize(src),IPL_DEPTH_8U,1); //存储分割结果图
 CvHistogram * hist  = cvCreateHist(1,&HistogramBins,CV_HIST_ARRAY,HistogramRange); 
 cvCalcHist(&src, hist);  //创建图像直方图
 
 cvNamedWindow("pImg", 1); //创建显示窗口
//计算图像的总的像素数目 
for(i=0; i<256;i++)
 {
  total += (int)cvQueryHistValue_1D(hist,i);
 }
 cout << total << endl;//实验图像总的像素数目为19200
 for (i=0; i<256; i++)
 {
 // cout << i << "====" << cvQueryHistValue_1D(hist,i) << endl;
  if((int)cvQueryHistValue_1D(hist,i)==0)
   continue;
  percentage[i] = cvQueryHistValue_1D(hist,i)/total; //计算每个灰度级的概率
 }
 for (i=0; i<256; i++)
 {
 // cout <<i<< "==="<< percentage[i] << endl;
  x += percentage[i];
  if (x >=0.5) //图像分为两块，计算从0开始到某灰度级像素概率之和大于或等于0.5
  {
   cout << i << endl;
   res[i] = cvCalculation(src, i, back) -0.5 – (cvCalculation(src, i, object) -0.5); //计算并存储目标函数 H(A,2)=Σ‖p(A_j )-0.5‖
  // cout << i << " ==  "<< res[i] << endl;
  }
 }
 
 // cout << sort(res, 256) << endl;
  cvThreshold(src, dst, (double)sort(res, 256), 255, CV_THRESH_BINARY);
  cvShowImage("pImg", dst);
  
  cvWaitKey(0);
  cvDestroyWindow("pImg");
 
  cvReleaseImage(&dst);
  
  return 0;
}
/*
函数功能：计算目标函数H(A,2)=Σ‖p(A_j )-0.5‖中的p(A_j )，此处只需算p(A_1 ),p(A_2 )
*/
double cvCalculation(IplImage *pImg, int n, entropy_state state)
{
 int start, end;
 if (state == back)
 {
  start = 0; 
  end = n;
 }
 if (state == object)
 {
  start = n;
  end = 256;
 }
 int  total = 0;
 double percentage = 0.0;
 CvHistogram * hist  = cvCreateHist(1,&HistogramBins,CV_HIST_ARRAY,HistogramRange);
 cvCalcHist(&pImg, hist);
 
//计算图像总的像素数目
for(int i=0; i<256;i++)
 {
 total += (int)cvQueryHistValue_1D(hist,i);
 }
 for(int i=start;i<end;i++)
 {
  if((int)cvQueryHistValue_1D(hist,i)==0)
   continue;
  percentage += cvQueryHistValue_1D(hist,i)/19200; 
 }
 
 return percentage;
}

/*
函数功能：求取目标函数H(A,2)=Σ‖p(A_j )-0.5‖的最小值。由于目标函数运算结果存储在res[256]数组中，故只需求该数组的最小值。
 */
double sort(double res[], int n)
{
 int i, j, k;
 double temp;
 for (i = 0; i<n; i++)
 {
  for (j = i+1; j<n; j++)
  {
   if (res[i]==0) continue;
   if (res[i] < res[j])
   {
    k = j;
    temp = res[j];
    res[i] = res[j];
    res[j] = temp;
   }
  }
 }
 cout << k << endl;
 return k;
}