欢迎互对答案~ // 第1题 int solution(string &S) { unordered_map<char, int> m; m[0] = -1; int n = S.size(); int res = 0; int cur = 0; for (int i = 0; i < n; ++i) { cur ^= (1 << (S[i] - 'a')); if (m.count(cur)) res = max(res, i - m[cur]); ...