#include<iostream> using namespace std; class Matrix { private: int* p; int rows, cols; public: Matrix(int r, int c) { rows = r; cols = c; p = new int[rows * cols]; } Matrix(Matrix& b) { rows = b.rows; cols = b.cols; p = new int[rows * cols]; for (int i = 0; i < rows * cols; i++) { p[i] = b.p[i]; } } void input() { cout << "请输入数组值：" << endl; for (int i = 0; i < rows * cols; i++) { cin >> p[i]; } } Matrix operator+(Matrix& b) { Matrix c(rows, cols); for (int i = 0; i < rows * cols; i++) { c.p[i] = p[i] + b.p[i]; } return c; } Matrix operator=(Matrix& b) { rows = b.rows; cols = b.cols; p = new int[rows * cols]; for (int i = 0; i < rows * cols; i++) { p[i] = b.p[i]; } } void show() { cout << "数组值为：" << endl; for (int i = 0; i < rows; i++) { for (int j = 0; j < cols; j++) { cout << p[i * cols + j] << " "; } cout << endl; } } ~Matrix() { delete[]p; } }; int main() { int r, c; cout << "请输入矩阵行数和列数：" << endl; cin >> r >> c; Matrix A(r, c); cout << "请输入矩阵A的值：" << endl; A.input(); A.show(); Matrix B(A); cout << "复制构造函数测试：" << endl; B.show(); Matrix C(r, c); C = A + B; cout << "加法运算符测试：" << endl; A.show(); Matrix D(r, c); D = A; cout << "赋值运算符测试：" << endl; D.show(); return 0; }请问这段代码为什么会报错

这段代码报错的原因是在 Matrix 类中的赋值运算符重载函数中没有返回值。应该将赋值运算符重载函数的返回值类型设置为 Matrix 类型，并在函数体中添加 return *this; 语句，将当前对象的引用返回。修改后的代码如下：

Matrix& operator=(Matrix& b) {
    rows = b.rows;
    cols = b.cols;
    p = new int[rows * cols];
    for (int i = 0; i < rows * cols; i++) {
        p[i] = b.p[i];
    }
    return *this;
}