class Solution { public: string trans(string s, int n) { // write code here string tmp, ret; for (int i = n - 1; i >= 0; --i) { char ch; if (s[i] >= 'a' && s[i] <= 'z') { ch = s[i] - 32; } else if (s[i] >= 'A' && s[i] <= 'Z') { ch = s[i] + 32; } else { tmp.push_back(s[i]); ret.insert(...