两种写法都可:

cat nowcoder.txt 
| awk '{split($0,arr,"/");print arr[3]}' 
| sort | uniq -c | sort -rn -k 1 |awk '{print $1,$2}'
cat nowcoder.txt 
| awk -F / '{print $3}' 
| sort | uniq -c | sort -rn -k 1 | awk '{print $1,$2}'