question on a simple for loop

[gdarian216]

I am tring to write a loop that will do exponents without using the cmath class.

// Output:  1 2 4 ... 2^(num - 1)
    // First num powers of 2, ^ denotes exponentiation/power
    // There is no operator to do exponentiation in C++.
    cout << "\n 6. ";
    int a = 1;
    cout << a;
    for (int i = 0; i <= num; i++)
    {
        int b = 2;
        int c = 0;
        int d = 1;
        while (d < num)
        {
        c *=b;
        }
        cout << c;
    }

this is what I have so far but im getting a infinite loop, i think im over thinking this can anyone help?

[Ganon11]

I am tring to write a loop that will do exponents without using the cmath class.

// Output:  1 2 4 ... 2^(num - 1)
    // First num powers of 2, ^ denotes exponentiation/power
    // There is no operator to do exponentiation in C++.
    cout << "\n 6. ";
    int a = 1;
    cout << a;
    for (int i = 0; i <= num; i++)
    {
        int b = 2;
        int c = 0;
        int d = 1;
        while (d < num)
        {
        c *=b;
        }
        cout << c;
    }

this is what I have so far but im getting a infinite loop, i think im over thinking this can anyone help?

Two issues:

1) Your while loop is being controlled by d - but you aren't changing d's value inside the loop. This is where your infinite loop comes from.

2) Inside this while loop, you multiply c by b to obtain a new c value. But c's initial value is 0. 0 times anything is 0, so your c value will always be 0.

You can probably do this with 2 nested for...loops and not bother with this while loop...