OJ系统一直提示：Segmentation fault:段错误，检查是否有数组越界，指针异常，访问到不应该访问的内存区域
但是一直检查不出来哪里有错误。二维动态数组这个问题困扰我好久了，求指点！
#include<iostream>
using namespace std;
//矩阵类定义
class Matrix
{
public:
Matrix(int, int);
void set(int, int);
friend istream& operator>>(istream &, Matrix&);
friend ostream& operator<<(ostream&, const Matrix&);
Matrix& operator*(Matrix&);
void DiagonalOrder();
void setZeros();
protected:
int** mat; //矩阵（二位数组）
int row; //行数
int col; //列数
};
Matrix temp(0,0); //定义全局对象，用于接受矩阵乘法结果
void Matrix::set(int n, int m)
{
row = n;
col = m;
mat = new int* [n];
for (int i = 0; i < n; i++)
{
mat[i] = new int[m];
}
if (mat == NULL)
{
cout << "allocation failure!\n";
return;
}
for (int i = 0; i < n; i++)
{
for (int j = 0; j < m; j++)
{
mat[i][j] = 0;
}
}
}
Matrix::Matrix(int n, int m) //构造函数，初始化行数列数与矩阵
{
row = n;
col = m;
if (m > 0 && n > 0)
{
mat = new int* [n];
for (int i = 0; i < n; i++)
{
mat[i] = new int[m];
}
if (mat == NULL)
{
cout << "allocation failure!\n";
return;
}
for (int i = 0; i < n; i++)
{
for (int j = 0; j < m; j++)
{
mat[i][j] = 0;
}
}
}
else
mat = NULL;
}
istream& operator>>(istream& input, Matrix& a) //重载输入运算符
{
for (int i = 0; i < a.row; i++)
{
for (int j = 0; j < a.col; j++)
{
input >> a.mat[i][j];
}
}
return input;
}
ostream& operator<<(ostream& output,const Matrix& a) //重载输出运算符
{
for (int i = 0; i < a.row; i++)
{
for (int j = 0; j < a.col-1; j++)
{
output << a.mat[i][j] << " ";
}
cout << a.mat[i][a.col - 1] << endl;
}
return output;
}
Matrix& Matrix::operator*(Matrix&a) //重载矩阵乘法
{
if (col == a.row)
{
temp.set(row, a.col);
for (int i = 0; i < temp.row; i++)
{
for (int j = 0; j < temp.col; j++)
{
int sum = 0;
int k = 0,o = 0;
while (k < col && o < a.row)
{
sum += mat[i][k] * a.mat[o][j];
k++; o++;
}
temp.mat[i][j] = sum;
}
}
return temp;
}
else
{
cout << "can't multiply!" << endl;
}
}
void Matrix::DiagonalOrder() //之字形打印
{
cout << mat[0][0] << " ";
int is_up = 1;
int x = 0, y = 0;
while (x >= 0 && x <= row - 1 && y >= 0 && y <= col - 1)
{
if (x == 0)
{
if (y == 0)
{
y++;
is_up = 0;
}
else if(y<col-1)
{
if (is_up == 0)
{
x++; y--;
}
else
{
y++;
is_up = 0;
}
}
else
{
is_up = 0;
x++;
}
}
else if (x == row - 1)
{
if (y>=0&&y<col-1)
{
if (is_up)
{
x--; y++;
}
else
{
y++;
is_up = 1;
}
}
}
else if (y == 0)
{
if (is_up == 1)
{
x--; y++;
}
else
{
x++;
is_up = 1;
}
}
else if (y == col - 1)
{
if (is_up == 1)
{
x++;
is_up = 0;
}
else
{
x++; y--;
}
}
else
{
if (is_up ==1)
{
x--; y++;
}
else
{
x++; y--;
}
}
if (x == row - 1 && y == col - 1)
{
cout << mat[x][y] << endl;
break;
}
else
cout << mat[x][y] << ' ';
}
}
void Matrix::setZeros() //将矩阵中有0的行和列全部置0
{
int** temp = new int* [row];
for (int i = 0; i < row; i++)
{
temp[i] = new int[col];
}
for (int i = 0; i < row; i++)
{
for (int j = 0; j < col; j++)
{
temp[i][j] = mat[i][j];
}
}
for (int i = 0; i < row; i++)
{
for (int j = 0; j < col; j++)
{
if (temp[i][j] == 0)
{
for (int k = 0; k < col; k++)
mat[i][k] = 0;
for (int o = 0; o < row; o++)
mat[o][j] = 0;
}
}
}
delete[]temp;
}
int main() {
int n, m;
while (cin >> m >> n) {
Matrix mat1(m, n);
cin >> mat1;
int x, y;
cin >> x >> y;
Matrix mat2(x, y);
cin >> mat2;
Matrix res = mat1 * mat2;
cout << res;
mat1.DiagonalOrder();
mat1.setZeros();
cout << mat1;
}
return 0;
}
