HackerRank ‘Uniq’ Command #3 problem solution

In this HackerRank ‘Uniq’ Command #3 problem-solution Given a text file, count the number of times each line repeats itself (only consider consecutive repetions). Display the count and the line, separated by a space. There shouldn’t be leading or trailing spaces. Please note that the uniq -c command by itself will generate the output in a different format.

This time, compare consecutive lines in a case insensitive manner. So, if a line X is followed by case variants, the output should count all of them as the same (but display only the form X in the second column).

So, as you might observe in the case below: aa, AA and Aa are all counted as instances of ‘aa’.

Sample Input

00

00

01

01

00

00

02

02

03

aa

AA

Aa

Sample Output

2 00

2 01

2 00

2 02

1 03

3 aa 

Explanation

00 is repeated twice

01 is repeated twice

00 is repeated twice

02 is repeated twice

03 occurs once

aa is repeated thrice (if we ignore case – AA, Aa are the same as ‘aa’)

Problem solution.

uniq -ic | sed 's/^ *//'

Second solution.

uniq -i -c | sed 's/^ *//g'

Third solution.

uniq -i -c | cut -c7-

Fourth solution.

uniq -c -i | sed 's/^ *//'