include

using namespace std;

void Usual_print() {

for (int i = 1; i < 10; i++)
{
    cout << i << "   ";
}
cout << "\n";
//cout << "9\n";

for (int i = 1; i < 10; i++)
{
    cout << "_   ";
}
//cout << "_\n";
cout << "\n";

}

int main() {

//第一个
Usual_print();

for (int i = 1; i < 10; i++)
{
    for (int j = 1; j < 10; j++)
    {
        if (i * j < 10)
        {
            cout << i * j << "   ";
        }
        else
        {
            cout << i * j << "  ";
        }
    }
    cout << "\n";

}

cout << "\n" ;

//第二个
Usual_print();
for (int i = 1; i < 10; i++)
{
    for (int j = 1; j <= i; j++)
    {
        if (i * j < 10) //\t 水平制表符无法控三格 故使用简单的if 判断对齐（下同）
        {
            cout << i * j << "   ";
        }

        else
        {
            cout << i * j << "  ";
        }
    }
    cout << "\n";

}

cout << "\n" ;

//第三个
Usual_print();
for (int i = 1; i < 10; i++)
{

    for (int p = i; p > 1; p--)
    {
        cout << "    ";
    }

    for (int j = i; j < 10; j++)
    {

        if (i * j < 10)
        {
            cout << i * j << "   ";
        }

        else
        {
            cout << i * j << "  ";
        }
    }
    cout << "\n";

}

return 0;

}