LeetCode-192: Word Frequency

192. Word Frequency

Solution

cat words.txt | tr -s ' ' '\n' | sort | uniq -c | sort -r | awk '{print $2 " " $1}'

Word Frequency Explanation

Here is a breakdown of each command in the pipeline:

Command	Explanation
cat words.txt	Reads the content of the file words.txt.
tr -s ' ' '\n'	Transforms spaces into newlines, putting each word on a separate line.
sort	Sorts the words alphabetically.
uniq -c	Counts the occurrences of each word and prefixes each word with its count.
sort -r	Sorts the words by frequency in descending order.
awk '{print $2 " " $1}'	Formats the output to display the word followed by its frequency.

Example Workflow

Given the input file words.txt containing:

this is a test this is only a test

The pipeline processes it as follows:

Step	Command	Output
Read file content	cat words.txt	this is a test this is only a test
Transform spaces to newlines	tr -s ' ' '\n'	this\nis\na\ntest\nthis\nis\nonly\na\ntest\n
Sort words alphabetically	sort	a\na\nis\nis\nonly\ntest\ntest\nthis\nthis\n
Count word occurrences	uniq -c	2 a\n2 is\n1 only\n2 test\n2 this\n
Sort by frequency descending	sort -r	2 this\n2 test\n2 is\n2 a\n1 only\n
Format output	awk '{print $2 " " $1}'	this 2\ntest 2\nis 2\na 2\nonly 1\n

Final Output

this 2
test 2
is 2
a 2
only 1