[C++] Super Short Solution !!!
Intuition\n Describe your first thoughts on how to solve this problem. \n\n# Approach\n Describe your approach to solving the problem. \n\n# Complexity\n- Time 
# Intuition\n<!-- Describe your first thoughts on how to solve this problem. -->\n\n# Approach\n<!-- Describe your approach to solving the problem. -->\n\n# Complexity\n- Time complexity:\n<!-- Add your time complexity here, e.g. $$O(n)$$ -->\n\n- Space complexity:\n<!-- Add your space complexity here, e.g. $$O(n)$$ -->\n\n# Code\n```\nclass Solution {\npublic:\n    int longestAwesome(string s) {\n        int n = s.size(), res = 0, seen[1024]{[0]=-1,[1 ... 1023]=n};\n        for(int i = 0, cur = 0; i < n; i++) {\n            cur ^= (1 << (s[i]-\'0\'));\n            for(int j = 0; j < 10; j++) res = max(res, i-seen[cur^(1 << j)]);\n            res = max(res, i-seen[cur]);\n            seen[cur] = min(i, seen[cur]);\n        }\n        return res;\n    }\n};\n```
['C++']