in c++ please

Explain what each instruction in the following procedure does.

void get_table(vector >& table)

{

int rows = table.size();

for (int r = 0; r < rows; r++) {

int columns = table[r].size();

for (int c = 0; c < columns; c++)

{

cout << "Enter value for (" << r << ", " << c << "): ";

cin >> table[r][c];

}

}

}

Explain what each of the following instructions does.

int main()

{

vector > m;

int rows, columns;

cout << "how many rows?: ";

cin >> rows;

m.resize(rows);

for (int r = 0; r < rows; r++)

{

cout << "how many columns for row " << r << "?: ";

cin >> columns;

m[r].resize(columns);

}