Longest substrings without repeating characters

Longest substrings without repeating characters is a draft programming task. It is not yet considered ready to be promoted as a complete task, for reasons that should be found in its talk page.

Task

Given a string find the longest substring without repeating characters.

Ring

<lang ring> see "working..." + nl see "Longest substrings without repeating characters are:" + nl str = "xyzyabcybdfd" see "Input: " + str + nl lenStr = len(str) strOk = [] lenOk = 0

for n = 1 to lenStr

   for m = 1 to lenStr-n+1
       temp = substr(str,n,m)
       add(strOk,temp)
   next

next

for n = len(strOk) to 1 step -1

   if len(strOK[n]) = 1
      del(strOK,n)
   ok

next

for n = 1 to len(strOK)

   for m = 1 to len(strOK)-1
       if len(strOK[m+1]) > len(strOK[m])
          temp = strOK[m]
          strOK[m] = strOK[m+1]
          strOK[m+1] = temp
       ok
   next

next

for n = 1 to len(strOK)

   for m = 1 to len(strOK)-1
       if len(strOK[m+1]) > len(strOK[m])
          temp = strOK[m]
          strOK[m] = strOK[m+1]
          strOK[m+1] = temp
       ok
   next

next

for n = 1 to len(strOK)

   flag = 1
   for m = 1 to len(strOK[n])
       for p = m+1 to len(strOK[n])
       if strOK[n][m] = strOK[n][p]
          flag = 0
          exit
       ok
       next
   next
   if flag = 1
      if len(strOK[n]) >= lenOk
         see "len = " + len(strOK[n]) + " : " + strOK[n] + nl
         lenOK = len(strOK[n])
      ok
   ok

next

see "done..." + nl </lang>

Output:

working...
Longest substrings without repeating characters are:
Input: xyzyabcybdfd
len = 5 : zyabc
len = 5 : cybdf
done...