double powerf(double base, double exponent)
{
double result;
int sign = 1;
double x = 0;
if (base < 0)
{
sign = -1;
base = fabs(base);
}
if (exponent == 0.0)
{
return (1.0*sign); // n**0 = 1
}
if ((base == 0.0) && (exponent > 0.0))
{
return (0.0); // 0**n = 0, n > 0
}
x = exponent - trunc (exponent);
if ((x == 0.0) && (fabs(exponent) <= 2147483647))
{
result = (sign*poweri(base, (int)trunc(exponent)));
}
else
{
result = (sign*exp(exponent * log(base)));
}
return result;
}
void convei(int zahl, char p[SSL])
{
int dig, j, ii = 0, sta, ani, z ;
double dum;
if (zahl < 0) {p[0] = 45; ++ii;}
z = fabs(zahl);
dum = log10( (double) z);
ani = (int) dum;
sta = poweri(10,ani);
for(j=ii; j <= ani+ii; j++) {
dig = z / sta ;
p[j] = dig + 48 ;
z = z - dig*sta;
sta = sta / 10 ;
}
p[j] = '\0';
}
double poweri(double x, int y)
{
//The following code goes into an endless loop when y is negative
// double value = 1.0;
// int count = 0;
// do
// {
// if(IS_ODD(exponent))
// {
// value *= base;
// }
// exponent >>= 1;
// base *= base;
// ++count;
// }
// while (exponent);
// return (value);
double temp;
if( y == 0)
{
return 1;
}
temp = poweri(x, y/2);
if (y%2 == 0)
{
return temp*temp;
}
else
{
if(y > 0)
return x*temp*temp;
else
return (temp*temp)/x;
}
}