自从你的函数声明:

void printMatrix(vector< vector<int> > *matrix)

指定一个指针，它本质上是通过引用传递的.但是，在 C++ 中，***避免使用指针并直接传递引用:

specifies a pointer, it is essentially passed by reference. However, in C++, it's better to avoid pointers and pass a reference directly:

void printMatrix(vector< vector<int> > &matrix)

和

printMatrix(matrix1); // Function call

这看起来像一个普通的函数调用，但它是通过引用传递的，如函数声明中所示.这可以避免不必要的指针取消引用.

This looks like a normal function call, but it is passed by reference as indicated in the function declaration. This saves you from unnecessary pointer dereferences.