[Leetcode] Word Frequency的笔记

单词出现的频率

题目如下

Write a bash script to calculate the frequency of each word in a text file words.txt.

For simplicity sake, you may assume:

- words.txt contains only lowercase characters and space ’ ’ characters.

- Each word must consist of lowercase characters only.

- Words are separated by one or more whitespace characters.

For example, assume that words.txt has the following content:

the day is sunny the the the sunny is is

Your script should output the following, sorted by descending frequency:

the 4 is 3 sunny 2 day 1

Note:

Don’t worry about handling ties, it is guaranteed that each word’s frequency count is unique.

题目大意: 计算每一个单词出现的频率，文件里面包含的是大于等于一个空白字符和小写字母

解题思路: 大体就是对文件的内容进行搜索，排序和统计，那么大体的命令就是grep，sort和uniq的命令来完成

代码如下

grep -Eo "[a-z]*" words.txt|sort -k1|uniq -c|sort -r|awk '{print $2" "$1}'

网上也有其他的答案

cat words.txt \ | tr -s ' ' '\n' \ | awk '{ words[$1]++ } END { for (key in words) print key, words[key] }' \ | sort -rn -k2

总体来说大同小异，扩展一下思路也是一个好事。