163. Missing Ranges

class Solution {
    public List<String> findMissingRanges(int[] nums, int lower, int upper) {
        List<String> res = new ArrayList<>();
        for (int num : nums) {
            if (num == Integer.MIN_VALUE) {
                lower = num + 1;
                continue;
            }
            
            if (lower < num - 1) {
                res.add(Integer.toString(lower) + "->" + Integer.toString(num - 1));
            } else if (lower == num - 1) {
                res.add(Integer.toString(lower));
            }
            
            if (num == Integer.MAX_VALUE) {
                return res;
            }
            lower = num + 1;
        }
        if (lower < upper) {
            res.add(Integer.toString(lower) + "->" + Integer.toString(upper));
        } else if (lower == upper) {
            res.add(Integer.toString(lower));
        }
        return res;
    }
}