Need help in calculating powers/roots

This is a discussion on Need help in calculating powers/roots within the C++ Programming forums, part of the General Programming Boards category; Hi, I wrote this function to calculate powers, like x^n. It works for integer values, but I can't get it ...

  1. #1
    Ham
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    Need help in calculating powers/roots

    Hi, I wrote this function to calculate powers, like x^n. It works for integer values, but I can't get it to calculate roots, like root 5 = 5^(1/2).

    Can someone tweek this a little bit for me? thx in advance.

    (The base is x, the exponent is n)

    int power(int x, int n)
    {
    int r; // result of calculation
    int p;

    r = 1;
    p = x;

    while (n > 0)
    {
    if (n % 2) // n is even
    r = r * p;

    p = p * p;
    n = n / 2;
    }

    return r;
    }

  2. #2
    and the hat of wrongness Salem's Avatar
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    > int power(int x, int n)
    How do you represent a half (0.5, 1/2) in the integer 'n'?
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  3. #3
    Toaster Zach L.'s Avatar
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    Root finding is much more difficult. You might want to look up the Newton root finding method (sometimes calles Newton-Raphson).
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