Link to the problem : Cf_739_E I am getting TLE in test case — 5 and have gone through the code many times, but cannot find any bug or optimisation. Any help is appreciated.

````````` ll solve() { string s; cin >> s; vector st(26, 0); string rm = ""; string final = ""; for (ll i = s.size() — 1; i >= 0; i--) { if (st[s[i] — 'a'] == 0) { st[s[i] — 'a'] = 1; rm = rm + s[i]; } else { st[s[i] — 'a']++; } } reverse(rm.begin(), rm.end()); ll total = 0; for (ll i = 0; i < rm.size(); i++) { if (st[rm[i] — 'a'] % (i + 1) != 0) { cout << -1 << endl; return 0; } st[rm[i] — 'a'] = st[rm[i] — 'a'] / (i + 1); total += st[rm[i] — 'a']; } vector st2(26, 0); for (ll i = 0; i < total; i++) { final = final + s[i]; st2[s[i] — 'a']++; } ll start = total; string tmp = final; string sb = final; for (ll i = 0; i < rm.size(); i++) { string tmp2 = ""; for (ll j = 0; j < tmp.size(); j++) { if (tmp[j] != rm[i]) { tmp2 += tmp[j]; } } tmp = tmp2; sb += tmp2; } if (sb != s) { cout << -1 << endl; return 0; } cout << final << " " << rm << endl; return 0; } ````````````