Abstract

The Uniq Command 3 problem from HackerRank.

Uniq Command 3

Problem

Uniq Command 3

Given a text file, count the number of times each line repeats itself (only consider consecutive repetitions). 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')

Solution

uniq-3.sh

#!/usr/bin/env bash

# shellcheck disable=SC2162
uniq -ci < /dev/stdin | awk '{$1=$1};1'