leetcode 的shell部分4道题整理

对shell的某些细节还不是十分熟悉，借鉴了好多别人的东西

1. Word Frequency

此题很简单，只要能排序就可以

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

2.

Valid Phone Numbers

cat file.txt | awk ‘/^\d{3}-\d{3}-\d{4}$/| /^\([0-9]{3}\) [0-9]{3}-[0-9]{4}$/‘

3.

Transpose File

cat file.txt| awk ‘{

max_nf = NF

max_nr = NR

for(x=1;x<=max_nf;x++){

vector[x,NR]=$x;

}

}

END{

for(x = 1;x <= max_nf;x++){

for( y = 1;y <= max_nr ; y++){

printf("%s",vector[x,y])

if (y < max_nr)

printf(" ")

}

if (x < max_nf)

printf("\n")

}

}

‘

4.

Tenth Line

cat file.txt|awk ‘NR==10‘