Leet Code 1018. Binary Prefix Divisible By 5

public List<Boolean> prefixesDivBy5(int[] nums) {
    List<Boolean> ans = new ArrayList<Boolean>();
    int sum = 0;
    for (int i = 0; i < nums.length; i++) {

        sum = (2 * sum + nums[i]) % 10;
        if (sum == 5 || sum == 0)
            ans.add(true);
        else
            ans.add(false);
    }
    return ans;
}