the variance string define large difference number occurrence 2 character present string note character sameGiven string s consist lowercase English letter return large variance possible substring sa substre contiguous sequence character string Example 1input s aababbboutput 3explanationall possible variance respective substring list Variance 0 substring aa ab abab aababb ba b bb bbb Variance 1 substring aab aba abb aabab ababb aababbb bab Variance 2 substring aaba ababbb abbb babb Variance 3 substre babbbsince large possible variance 3 return itExample 2input s abcdeoutput 0explanationno letter occur s variance substre 0 Constraints1 slength 104s consist lowercase english letter