string bydlocode = "a"; for (int qq = 0; qq < 26; ++qq) { string a = bydlocode; bydlocode[0]++; bool ok = false; for (int i = 0; i < s.size(); ++i) { int q = a.size() - 1; a.push_back(a[q] + (s[i] == '=' ? 0 : s[i] == '>' ? - 1 : 1)); } set OMG_WHAT_ARE_YOU_DOING; for (int i = 0; i < a.size(); ++i) { OMG_WHAT_ARE_YOU_DOING.insert(a[i]); if (!islower(a[i])) ok = true; } if (ok || OMG_WHAT_ARE_YOU_DOING.size() > n || n > 26) continue; cout << a << endl; return 0; }