Calculating nth root in Java using power method

Question

I was trying to get a cubic root in java using Math.pow(n, 1.0/3) but because it divides doubles, it doesn\'t return the exact answer. For example, with 125, this g

Answer 1

Here is the solution without using Java's Math.pow function. It will give you nearly nth root

public class NthRoot {

public static void main(String[] args) {
    try (Scanner scanner = new Scanner(System.in)) {
        int testcases = scanner.nextInt();
        while (testcases-- > 0) {
            int root = scanner.nextInt();
            int number = scanner.nextInt();
            double rootValue = compute(number, root) * 1000.0 / 1000.0;
            System.out.println((int) rootValue);
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
}

private static double compute(int number, int root) {
    double xPre = Math.random() % 10;
    double error = 0.0000001;
    double delX = 2147483647;
    double current = 0.0;

    while (delX > error) {
        current = ((root - 1.0) * xPre + (double) number / Math.pow(xPre, root - 1)) / (double) root;
        delX = Math.abs(current - xPre);
        xPre = current;
    }
    return current;
}