Create a power() function that correctly handles negative powers. - C Function

C examples for Function:Utility Function

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Description

Create a power() function that correctly handles negative powers.

Demo Code

#include <stdio.h>
#include <stdlib.h> // prototype for abs() 

double power(double base, int exponent);

int main(void){
  double base, output;
  int exponent;/*w  w w .j  a v  a2 s.  c o m*/

  printf("Enter a :double: base and :int: exponent: ");

  while (scanf("%lf %d", &base, &exponent) == 2){
    output = power(base, exponent);

    printf("%f ^ %d = %f \n", base, exponent, output);

    printf("Enter a :double: base and :int: exponent: ");
  }
  return 0;
}

double power(double base, int exponent){
  double power = base;

  if (base == 0){
    if (exponent == 0){
      printf("Warning: 0 ^ 0 is undefined. Using 1.\n");
      return 1.0;
    }
    else
      return 0;
  }

  for (int i = 1; i < abs(exponent); i++){
    power *= base;
  }

  if (exponent < 0)
    power = 1 / power;

  return power;
}

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