2605. Form Smallest Number From Two Digit Arrays

Given two arrays of unique digits nums1 and nums2, return the smallest number that contains at least one digit from each array.

class Solution {
public:
    int minNumber(vector<int>& nums1, vector<int>& nums2) {
        unordered_set<int> us1(begin(nums1), end(nums1)), us2(begin(nums2), end(nums2));
        int res = 100;
        for(int i = 1; i <= 9; i++) {
            if(!us1.count(i)) continue;
            for(int j = 1; j <= 9; j++) {
                if(!us2.count(j)) continue;
                if(i == j) res = min(res, j);
                else res = min({res, i * 10 + j, j * 10 + i});
            }
        }
        return res;
    }
};