Find longest substring without repeating characters.

Description:

Given a string, find the longest substrings without repeating characters. Iterate through the given string, find the longest maximum substrings.

Code:

? 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 import java.util.HashSet; import java.util.Set;   public class MyLongestSubstr {       private Set<String> subStrList = new HashSet<String>();     private int finalSubStrSize = 0;           public Set<String> getLongestSubstr(String input){         //reset instance variables         subStrList.clear();         finalSubStrSize = 0;         // have a boolean flag on each character ascii value         boolean[] flag = new boolean[256];         int j = 0;         char[] inputCharArr = input.toCharArray();         for (int i = 0; i < inputCharArr.length; i++) {             char c = inputCharArr[i];             if (flag[c]) {                 extractSubString(inputCharArr,j,i);                 for (int k = j; k < i; k++) {                     if (inputCharArr[k] == c) {                         j = k + 1;                         break;                     }                     flag[inputCharArr[k]] = false;                 }               } else {                 flag[c] = true;             }         }         extractSubString(inputCharArr,j,inputCharArr.length);         return subStrList;     }           private String extractSubString(char[] inputArr, int start, int end){                   StringBuilder sb = new StringBuilder();         for(int i=start;i<end;i++){             sb.append(inputArr[i]);         }         String subStr = sb.toString();         if(subStr.length() > finalSubStrSize){             finalSubStrSize = subStr.length();             subStrList.clear();             subStrList.add(subStr);         } else if(subStr.length() == finalSubStrSize){             subStrList.add(subStr);         }                   return sb.toString();     }       public static void main(String a[]){         MyLongestSubstr mls = new MyLongestSubstr();         System.out.println(mls.getLongestSubstr("govindblog"));         System.out.println(mls.getLongestSubstr("java_language_is_sweet"));         System.out.println(mls.getLongestSubstr("java_java_java_java"));         System.out.println(mls.getLongestSubstr("abcabcbb"));     } }

Output:

[vindblog, govindbl] [uage_is] [va_j, _jav] [bca, abc, cab]