package question;

/**
 * @author Roderland
 * @since 1.0
 */
public class Question395 {
 public static void main(String[] args) {
 System.out.println(new Question395().longestSubstring("ababbc", 2));
 }

 public int longestSubstring(String s, int k) {
 if (s.length()<k) return 0;
 int[] map = new int[26];
 for (int i = 0; i < s.length(); i++) {
 map[s.charAt(i)-'a']++;
 }
 int i=0;
 for (; i < map.length; i++) {
 if (map[i]>0 && map[i]<k) break;
 }
 char c = (char)('a'+i);
 int j = 0;
 for (; j < s.length(); j++) {
 if (s.charAt(j)==c) break;
 }
 if (j>=s.length()) return s.length();
 return Math.max(longestSubstring(s.substring(0, j), k),
 longestSubstring(s.substring(j+1, s.length()), k));
 }
}