classSolution{ public String frequencySort(String s){ int[] map = newint[128]; for (char c : s.toCharArray()) { map[c]++; } char[] res = newchar[s.length()]; int pos = 0; while (pos < s.length()) { char max = 0; for (char c = 0; c < map.length; c++) { if (map[c] > map[max]) max = c; } int repeat = map[max]; for (int i = 0; i < repeat; i++) { res[pos++] = max; map[max]--; } } returnnew String(res); } }