所以我正在練習編碼在c + +中,我正試圖編寫一個矩陣(存儲爲數組)的類與相關的重載操作。分割錯誤過載ostream(<<)
我已經儘可能定義類,並試圖超載運算符,但我目前的代碼導致了一個分段錯誤(我在Ubuntu中使用g ++進行編譯)。我在網上看過,有類似問題的人往往會忘記在他們的超載函數中返回os,但是我已經這樣做了,所以我不知道我的問題會是什麼。此外,我的重載操作員在導致分段錯誤之前工作多次。
任何幫助將不勝感激。
這裏是我的代碼:
#include<iostream>
#include<stdlib.h> // for c style exit
using namespace std;
class matrix
{
// Friends
friend ostream & operator<<(ostream &os, const matrix &mat);
friend istream & operator>>(istream &is, matrix &mat);
private:
double *mdata;
int rows,columns;
public:
// Default constructor
matrix(){mdata=0; rows=columns=0;}
// Parameterized constructor
matrix(int m, int n){mdata = new double[ m*n ]; rows = m; columns = n;}
// Copy constructor
matrix(matrix &mat)
// Destructor
~matrix(){delete[] mdata; cout<<"Destructing array."<<endl;}
// Access functions
int getrows() const {return rows;} // Return number of rows
int getcols() const {return columns;} // Return number of columns
int index(int m, int n) const // Return position in array of element (m,n)
{
if(m>0 && m<=rows && n>0 && n<=columns) return (n-1)+(m-1)*columns;
else {cout<<"Error: out of range"<<endl; exit(1);}
}
double & operator()(int m, int n)const {return mdata[index(m,n)];}
// Other access functions go here
double & operator[](int i) {return mdata[i];}
// Other functions
// Copy Assignment operator
matrix & operator=(matrix &mat);
};
// Member functions defined outside class
matrix::matrix(matrix &mat){
rows = mat.getrows();
columns = mat.getcols();
for(int j = 0; j<rows*columns; j++){mdata[j] = mat[j];}
}
matrix & matrix::operator=(matrix &mat){
if (&mat == this) return *this;
delete[] mdata; rows = 0; columns = 0;
rows = mat.getrows(); columns = mat.getcols();
if(rows>0&&columns>0){
mdata = new double[(columns-1) + (rows-1)*columns + 1];
for(int j = 0; j<rows*columns; j++){mdata[j] = mat[j];}
}
return *this;
}
// Overload insertion to output stream for matrices
ostream & operator<<(ostream &os, const matrix &mat){
for(int j = 0;j<mat.rows;j++){
for(int k = 0;k<mat.columns;k++){
os << mat(j+1,k+1) << " ";
}
os << endl;
}
return os;
}
// Main program
int main(){
// Demonstrate default constructor
matrix a1;
cout<<a1;
// Parameterized constructor
const int m(2),n(2);
matrix a2(m,n);
// Set values for a2 here
a2[0] = 1; a2[1] = 2; a2[2] = 3; a2[3] = 4;
// Print matrix a2
cout<<a2;
// Deep copy by assignment: define new matrix a3 then copy from a2 to a3
matrix a3(m,n);
cout<<a3;
a3=a2;
cout<<a3;
// Modify contents of original matrix and show assigned matrix is unchanged here
a2[0] = 5;
cout<<a2;
cout<<a3; //here is where segmentation fault occurs
return 0;
}
我建議先修復複製構造函數和賦值運算符。 – juanchopanza
然後運行一個調試器,因爲你的代碼充滿了微不足道的錯誤。 – juanchopanza
*我已經定義了課程* - 你沒有。這個矩陣類只需要一個兩行的main()程序就可以完全平坦。 '{matrix m(1,2);矩陣m2 = m;}' – PaulMcKenzie