幂函数C ++

Question

I have given the code below, I have tried to workout how the function works. I don't understand what happens when you enter the while loop. Does result get multiplied by the power of the value of x? Why does n get lower? I mainly don't understand what result *=x; does.

//power(x, n) raises integer x to the power n
//no negative powers
int power(int x, unsigned n)
{
    int result=1;
    while (n>0)
    {
        result *= x;
        --n;
    }
    return result;
}

Answer 1

Hint, the following lines are equivalent (in this context):

result *= x;
result = result * x;

--n;
n = n - 1;

So your function written as simply as possible:

int power(int base, int exponent) {
    int result = 1;
    while (exponent > 0) {
        result = result * base;
        exponent = exponent - 1;
    }
    return result;
}

You should have an easier time understanding it now.

Answer 2

The power function of (x,n) is just multiply x by n times.

result *= x; means result = results * x; .

while loop make sure the x has been multiplied by n times.

--n means n = n - 1 . If n=0 , it means x has been multiplied by n times. Then, the loop ends.