leetcode

1980.cpp (468B)

 class Solution {
   public:
     string findDifferentBinaryString(const vector<string> &nums) {
         const unordered_set<string> us(begin(nums), end(nums));
         const int n = nums.size();
 
         for (int mask = 0, crnt = 0; mask < (1 << n); crnt = ++mask) {
             string s(n, '0');
             for (int i = n - 1; i >= 0; i--, crnt >>= 1)
                 if (crnt & 1) s[i]++;
             if (!us.count(s)) return s;
         }
         return "";
     }
 };