Next lexicographical string - PrismoSkills

Next lexicographical string - PrismoSkills

Problem: Write code to print the lexicographical next string for a given string.

(As in dictionary, next word after this word but having similar letters) For ex:

i/p abcd

o/p abdc

i/p abcged

o/p abdceg

Solution:

Find the number of characters at the end of string that are sorted

decreasingly e.g. in "abcgda" the length of such sub-string is 3 ( "gda" ).

Then look at the char before this sub-string (here it is 'c' ).

This character must be replaced with the smallest character in

the decreasing sub-sequence which is bigger than this char (here it's 'd').

Then sort the decreasing sub-string to be increasing

So the next lexicographical string of "abcgda" is "abdacg" ('d' is replaced

with 'c' and then "gca" is sorted to be "acg")

Note If a string is sorted decreasingly like "dcba" it's next char does

not exist so it's next string doesn't exist

Read full article from Next lexicographical string - PrismoSkills