Implement pow(x,n) in C

Question

Implement pow(x, n), which calculates x raised to the power n (i.e., xn).

 

Constraints:

1. -100.0 < x < 100.0
2. -231 <= n <= 231-1
3. n is an integer.
4. Either x is not zero or n > 0.
5. -104 <= xn <= 104

Answer 1

/**

* @brief Calculates x raised to the power n.

*

* @param x The base.

* @param n The exponent.

* @return The result of x raised to the power n.

*/

double myPow(double x, int n) {

// Base cases: n = 0 or n = 1if (n == 0) return 1.0;

if (n == 1) return x;

double result = 1.0;

long long N = n; // Using long long to safely handle edge case of n = -2^31

// If n is negative, take the reciprocal of x and negate nif (N < 0) {

x = 1 / x;

N = -N;

}

// Current product, initialized to xdouble current_product = x;

// Exponentiation by squaringfor (; N; N >>= 1) {

// If the last bit of N is set (N is odd), multiply the result by the current productif (N & 1) {

result *= current_product;

}

// Square the current product for the next iteration

current_product *= current_product;

}

return result;

}