How to find longest substring with at most two unique characters?

How to find longest substring with at most two unique characters?

Identify all the substrings of the given input string and check each substring with no of unique characters in it and pick the one with maximum length. Time Complexity: O (N3), N^2 for all finding the substrings and O (N) for each substring while checking unique characters.

How to check the length of a substring?

At each step, keep track of length of maximum substring by doing curr_end-curr_start. To check whether substring has only 2 unique characters, maintain an array of size 26 ( 26 alphabets) and array with filled with the count of characters in the string to the respective index. 0th index for ‘a’ and 25th index for z.

Which is the longest run of two unique characters?

Find the longest run of consecutive characters in a string that contains only two unique characters; if there is a tie, return the rightmost. For instance, given input string abcabcabcbcbc, the longest run of two characters is the 6-character run of bcbcbc that ends the string.

How to count number of substrings with exactly k distinct characters?

Recommended: Please solve it on “ PRACTICE ” first, before moving on to the solution. If the length of string is n, then there can be n* (n+1)/2 possible substrings. A simple way is to generate all the substring and check each one whether it has exactly k unique characters or not.

Which is the longest substring for abdefgabef?

For “ABDEFGABEF”, the longest substring are “BDEFGA” and “DEFGAB”, with length 6. For “BBBB” the longest substring is “B”, with length 1. For “GEEKSFORGEEKS”, there are two longest substrings shown in the below diagrams, with length 7.

Which is the longest Index in a string?

Your index is the max length Depends on your definition of repeated characters: if you mean consecutive, then the approved solution is slick, but not of characters appearing more than once ( e.g.: pwwkewabmb -> ‘kewabmb’ ).

Method 1 (Simple : O (n3)): We can consider all substrings one by one and check for each substring whether it contains all unique characters or not. There will be n* (n+1)/2 substrings. Whether a substring contains all unique characters or not can be checked in linear time by scanning it from left to right and keeping a map of visited characters.