Sometimes, when the files are different, we want have a summary of how far off they are. In a case of well formatted data, we might also want to know by how much the values differ. A practical example would be comparing some kind of a usage report against the expected values.
The input file DATA3.txt will contain 5 sets of input. Each set starts with a line having an integer 0 <= N <= 5 and another line with an integer 0 <= M <= 5. Followed by N+M lines with the contents of the two files. There will be break line containing three minus signs --- after each set.
Each line inside a "file" to be compared is a string-integer pair separated by a single space. The string is a 3 character word (lower case alpha characters), the integer is a non-negative integer less than 100.
Each "file" is in a sorted order according to the leading string. The string keys in each file are unique.
The output file OUT3.txt will contain 5 lines of output, contain a pair of integer sums, separated by a space. The first integer is the total number of lines missing between two files. The second integer is a sum of the absolute differences in the values of the lines where string keys match.
Notes on the sample below: in the first case both files have just a single line. The keys are the same, so zero lines are missing, but the values differ by one. In the second case the first file is missing a line with "baz" while the second file is also missing a line with "foo", so there is a total of two missing lines. The remaining lines have their values differ by one.
1 1 foo 42 foo 41 --- 2 2 bar 1 foo 42 bar 2 baz 40 ---
0 1 2 1