/* write a function double power(double base, int exp) that finds and 
returns base^exp

0^0 returns 1
exp<0 base !=0 - function will not be called

2^(-3)=1/(2^3)


in main test the function on 5 random pairs of base, exp
and compare to the result of the math.h library function pow

*/

#include<stdio.h>
#include<math.h>
#include<stdlib.h>
#include<time.h>

double power(double, int); //function prototype

int main(){
	srand(time(NULL));
	int i, exp;
	double math_result, our_result,base;
	printf("enter base \n");
	for(i=0;i<5;i++){
		scanf("%lf",&base);
		//for exponent we will generate a random number between -5 and 5
		exp= -5+rand()%11;
		if(exp<0 && base!=0){
			math_result=pow(base, exp);
			our_result=power(base, exp);
			printf("math_result %f^%d %f\n",base, exp, math_result);
			printf("our result %f^%d %f\n",base, exp, our_result);
		}
		else if(exp>=0){
			math_result=pow(base, exp);
                        our_result=power(base, exp);
			printf("math_result %f^%d %f\n",base, exp, math_result);
 	                printf("our result %f^%d %f\n",base, exp, our_result);
		}
		else
			printf("invalid input\n");
	}
	return 0;

}


double power(double base, int exp){
	if(base == 0 && exp == 0)
		return 1;

	//base^exp=base*base*base....*base 
	//exp<0   base^exp=1/(base*base*base....*base)


	int i;
	double product=1.0;
	for(i=0;i<(int)(fabs(exp)); i++)
		product*=base;
	if(exp>0)
		return product;
	else
		return 1/product;
}