To write a Java program for finding the nth multiple of a number in the Fibonacci series, we can follow the steps below:
First, we define a function that takes two integer arguments, n and k, where n is the index of the multiple we want to find, and k is the number we want to find multiples of.
We initialize two integer variables, a and b, to 0 and 1 respectively, as these are the first two numbers in the Fibonacci series.
We then loop from 2 to n, calculating each number in the Fibonacci series by adding the two previous numbers, and storing them in a and b.
Inside the loop, we check if a is a multiple of k using the modulo operator (%). If it is, we decrement n by 1. When n reaches 0, we return a.
If a is not a multiple of k, we continue the loop until we find the nth multiple of k in the Fibonacci series.
Here is the code for the program:
public static int nthFibonacciMultiple(int n, int k) { int a = 0; int b = 1; for (int i = 2; i <= n; i++) { int c = a + b; a = b; b = c; if (a % k == 0) { n--; if (n == 0) { return a; } } } return -1; }
This function returns the nth multiple of k in the Fibonacci series, or -1 if there is no such multiple.