It's written in Python, in order to run the code, just call thefunction maxsequence(str). For instance, maxsequence('aaaaaannndmdejlsfnsfsssssnnnnnxxx') or maxsequence("kdkdkdkdjeeeiwwwnnnmdnnsbjdiiiiiiiiiidndbbcbbccbcvcvdddcjdjdjwwwwwwkkkkxlxllllllll")

def maxsequence(str):

count = 1 # count if the letters are repeat step = 0 # once the next letter changed, step = count. countArray = [] # put all the sequence numbers in an array lettersArray = [] # put all the repeat letters in an array max = 0 # for calculating the max of the array, it needs two indexes to do that indexFirst = 0 indexNext = 1 i = 0 while(i<len(str) and i<=(len(str)-2)): if(str[i]==str[i+1]): count += 1 step = count else: lettersArray.append(str[i]) step = count countArray.append(step) count = 1 i += 1 countArray.append(step) lettersArray.append(str[i]) while(countArray[indexFirst]>=countArray[indexNext] and indexNext<(len(countArray)-1)): indexNext += 1 if(countArray[indexFirst]<=countArray[indexNext]): indexFirst = indexNext max = countArray[indexFirst] for i in range(len(lettersArray)): print lettersArray[i],"=",countArray[i] print "The max sequence is:", max return max 

It's written in Python, in order to run the code, just call thefunction maxsequence(str). For instance, maxsequence('aaaaaannndmdejlsfnsfsssssnnnnnxxx') or maxsequence("kdkdkdkdjeeeiwwwnnnmdnnsbjdiiiiiiiiiidndbbcbbccbcvcvdddcjdjdjwwwwwwkkkkxlxllllllll")

def maxsequence(str): count = 1 # count if the letters are repeat step = 0 # once the next letter changed, step = count. countArray = [] # put all the sequence numbers in an array lettersArray = [] # put all the repeat letters in an array max = 0 # for calculating the max of the array, it needs two indexes to do that indexFirst = 0 indexNext = 1 i = 0 while(i<len(str) and i<=(len(str)-2)): if(str[i]==str[i+1]): count += 1 step = count else: lettersArray.append(str[i]) step = count countArray.append(step) count = 1 i += 1 countArray.append(step) lettersArray.append(str[i]) while(countArray[indexFirst]>=countArray[indexNext] and indexNext<(len(countArray)-1)): indexNext += 1 if(countArray[indexFirst]<=countArray[indexNext]): indexFirst = indexNext max = countArray[indexFirst] for i in range(len(lettersArray)): print lettersArray[i],"=",countArray[i] print "The max sequence is:", max return max