JAVA QUESTION Write a method that computes the following series below: HINT: Use a loop and Math.pow() to raise t to the nth power.

Answer 1

You can use the built-in Java Math.pow(), but if you have to build your own methods, the below are recursion methods:

Assume: n is not negative integer

// O(log(N)) solution

public static double pow_logn(double t, int n) {

if (n == 0) return 1;

//if (n == 1) return t;

double p = pow_logn(t, n / 2);

return (n % 2 == 0) ? p * p : p * p * t;

}

// O(log3(N)) solution -> Faster than pow_logn

public static double pow_log3n(double t, int n) {

if (n == 0) return 1;

//if (n == 1) return t;

double p = pow_log3n(t, n / 3);

int r = n % 3;

if (r == 0) return p * p * p;

if (r == 1) return p * p * p * t;

// r = 2

return p * p * p * t * t;

}