Yet another C++ Question...

[pac1085]

Heres what the problem says to do:

Write a function PowerOf() that calculates and returns the value of x^n. (Hint: A for loop can be used to calculate the power.) Use the function header:
double PowerOf(double x, int n)
/*Returns x to the ntn power
n assumed >=0 */

My question is what do I put in the for loop it says to use to calculate the power? Im not very good in math questions like this, so any help would be greatly appreciated.

 

nevermind

 

[MC]

PowerOf(double x, int n){
If(x==1)
return x;
double result = 1; //Use to store result of x^n
else {
for(int i=1; i<n; i++){
result=result*x;
}
return result;
}

Hope this will help...

 

[pac1085]

Thanks for the replys, MingChia, I had to change your code around a little bit, or I would get an error saying result wasnt declared or something. I still have a problem though...when I input PowerOf(2,10) it should display 1024, but it only displays 512...any clue why?

 

[BowDown]

I write 'C' but it's the same here:

double PowerOf (double x, int n)

{
int counter;
double total;

if (n == 1)
return (x);
else
for (total = x, counter = 1; counter < n; total *= x, counter++)
;
return (total);
}

It works I have tried it out .

 

[pac1085]

Thanks BowDown, I owe ya one

 

[BowDown]

\\ Here's the whole thing if you want it .

\\ I set it to only print to the hundreths position

#include <stdio.h>

void get_num (double *, int *);
double PowerOf (double, int);
void print_out (double);

int main (void)

{
int x;
double y;
double total;

get_num (&amp;y, &amp;x);

total = PowerOf (y, x);

print_out (total);

return (0);
}

void get_num (double *y, int *x)

{
char ch;

printf(&quot;Please enter the number to be changed: &quot;
scanf(&quot;%lf%c&quot;, y, &amp;ch);

printf(&quot;\nPlease enter the power to be raised to: &quot;
scanf(&quot;%d%c&quot;, x, &amp;ch);
}


double PowerOf (double x, int n)

{
int counter;
double total;

if (n == 1)
return (x);
else
for (total = x, counter = 1; counter < n; total *= x, counter++)
;
return (total);
}

void print_out (double total)

{
printf(&quot;\nYour results is %.2f!&quot;, total);
}

 

[Mark R]

You need to include:

if (n==0) return 1;

The instructions state than n>=0.

 

[pac1085]

Cool, Heres what I got (It works...but I havent set it up to let the user input the values )

#include <iostream.h>
#include <conio.h>


double PowerOf (double x, int n);

int main()
{


cout << PowerOf(2,10) << &quot;\n&quot;;

cout << &quot;\nPress any key to continue\n&quot;;
getch();
return 0;
}

double PowerOf (double x, int n)

{
int counter;
double total;

if (n == 1)
return (x);
else
for (total = x, counter = 1; counter < n; total *= x, counter++);
return (total);
}

 

[HigherGround]

and just for the hell of it here's another version ...


#include <iostream.h>

double powerof(double x, int n)
{
double rvalue = x;
while(--n) rvalue *=x;
return rvalue;
}

int main( )
{
double _base;
int _exp;

cout << &quot;Enter base value : &quot;;
cin >> _base;
cout << &quot;Enter exponent value : &quot;;
cin >> _exp;

if(_exp >= 0)
switch(_exp)
{
case 0:
cout << endl << _base << &quot; raised to 0 : 1&quot; << endl; break;
default:
cout << endl << _base << &quot; raised to &quot; << _exp << &quot; : &quot; << powerof(_base, _exp) << endl; break;
}
else
cout << &quot;Illegal exponent value&quot; << endl;
}

 

[BowDown]

Hehe... Cin and Cout; all greak to me .

Yes I did forget the if (n==0). Noticed that after, but figured she was smart enough to catch that.

 

[pac1085]

im not a she i just felt like using the woman icon

 

[BowDown]

Ah, so you're just a B!ich...

j/k...