#K3611. Longest Substring with At Most Two Distinct Characters
Longest Substring with At Most Two Distinct Characters
Longest Substring with At Most Two Distinct Characters
Given a string S, find the longest contiguous substring of S that contains at most two distinct characters. In other words, if we denote the substring as S[i...j], then it must satisfy
\(\#\{c \mid c \in S[i...j]\} \le 2\).
If there exist multiple longest substrings, output the lexicographically smallest one.
Example:
- Input:
abcbbbbcccbdddadacb - Output:
bcbbbbcccb
inputFormat
The input is read from standard input (stdin) and consists of a single line containing a non-empty string S composed of lowercase English letters.
outputFormat
Output to standard output (stdout) the longest substring of S that contains at most two distinct characters. If there are multiple valid answers, output the lexicographically smallest one.
abcbbbbcccbdddadacbbcbbbbcccb