merge specific line using awk and sed

Question

I want to merge specific line

Input :

AAA
BBB
CCC
DDD
EEE
AAA
BBB
DDD
CCC
EEE

Output Should be

AAA
BBB
CCC DDD
EEE
AAA
BBB
DDD
CCC EEE

I want to search CCC and merge next line with it.

I have tried with awk command but didn't get success

Answer 1

Use awk patterns, if the line matches /CCC/ then print the line with a space at the end and go on to the next line. Otherwise (1), print the line.

awk '/CCC/ { printf("%s ", $0); next } 1' file

Answer 2

Using sed:

sed '/CCC/ { N; s/\n/ / }' file

Using awk:

awk '{ ORS=(/CCC/ ? FS : RS) }1' file