/*
    81__union.c
    -----
    Program demonstrira rad s unijama (union-ima).
*/
 
#include <stdio.h>
#include <math.h>
 
typedef union {
    double fexp;
    int nexp;
} nvals;
 
typedef struct {
    double x;
    char flag;
    nvals exp;
} values;
 
double power(values a);
 
int main() {
    values a;
    int i;
    double n,y;
 
    printf("Unesite vrijednost za x: ");
    scanf("%lf", &a.x);
    printf("Unesite vrijednost za n: ");
    scanf("%lf", &n);
    i=(int)n;
    a.flag=(i == n) ? 'i' :'f';
    if (a.flag == 'i')
        a.exp.nexp = i;
    else 
        a.exp.fexp = n;
 
    if (a.flag == 'f' && a.x <= 0.0) 
        printf("Greska pri unosu!\n");
    else {
        y=power(a);
        printf("y= %.4f\n",y);
    }
 
    return 0;
}
 
double power(values a) {
    int i;
    double y=a.x;
 
    if (a.flag == 'i') 
        if (a.exp.nexp == 0)
            y=1.0;
        else {
            for (i=1;i<abs(a.exp.nexp); ++i)
                y *=a.x;
            if (a.exp.nexp < 0)
                y=1./y;
        }
    else 
        y=exp(a.exp.fexp*log(a.x));
 
    return y;
}