Josephus Problem

Problem Statement - https://practice.geeksforgeeks.org/problems/game-of-death-in-a-circle1840/1

class Solution {
    static int safePos(int n, int k) {
        // code here

        ArrayList<Integer> list = new ArrayList<>();
        for(int i=0; i<n; i++) {
            list.add(i+1);
        }
         // As we are dealing with 0 indexed base arraylist
        return helper(list, k-1, 0);

    }

    static int helper(ArrayList<Integer> list, int k, int curr) {
        // As soon as the size of the list becomes 1, return that number
        if(list.size()==1)
        {
            return list.get(0);
        }
        // get the next index for which element should be removed
        int index = (curr+k)%(list.size());
        // remove the element
        list.remove(index);
        // recursively call the helper method on the smaller input
        return helper(list, k, index);
    }
};

Time complexity - O(n)