2442-count-number-of-distinct-integers-after-reverse-operations.java

class Solution {
    public int countDistinctIntegers(int[] nums) {
        Set<Integer> set = new HashSet<>();
        for(int i = 0; i < nums.length; i++) {
            set.add(nums[i]);
            set.add(reverse(nums[i]));
        }
        return set.size();
    }

    public int reverse(int num) {
        int res = 0;
        while(num > 0) {
            int last = num % 10;
            res = res * 10 + last;
            num = num / 10;
        }
        return res;
    }
}