✔ 最佳答案
Here's the pseudo code:
get input file name from user
open file
if input file openeed successfully
..get output file name from user
..if output file opened successfully
....while not eof (input file)
......read line from input file to buffer
......write line from buffer to output file
......write additional newline to output file
....end while
....close output file
..end if
..close input file
endif
-- optional extra stuff
rename input file (e.g. rename to original_name.bak)
rename output file to original name of input file
Now all you need to do is code this up in C++.