Practice Lists and Loops with the exercise "Simple Diff Tool"

Learning Opportunities

This puzzle can be solved using the following concepts. Practice using these concepts and improve your skills.

Statement

Goal

A product owner was asked to develop a text diff tool. Unfortunately he was a bit confused because there is no id on text lines.
So after a short time he discovered only two ways to identify lines: by their number or by their content.
As he did not know which one is better, he asked his developer team to add the identifier method as a configuration parameter of the tool.

The behavior of the tool is defined as follows:
Step 1: The tool matches lines from the revised file to the ones in the original file, based on the configuration parameter value.
• If set to BY_NUMBER, lines are considered matched if they have the same line number, regardless of their contents.
• If set to BY_CONTENT, lines are considered matched if their contents are identical, regardless of their line numbers.
Step 2: The tool processes differences between matched lines, based on the configuration parameter value.
• If set to BY_NUMBER, the tool shall output CHANGE for each pair of matched lines with unequal content.
• If set to BY_CONTENT, the tool shall output MOVE for each pair of matched lines with unequal line numbers.
Step 3: The tool processes differences between unmatched lines, regardless of the configuration parameter value.
• The tool shall output DELETE for every unmatched line that exists only in the original file.
• The tool shall output ADD for every unmatched line that exists only in the revised file.

Input

Line 1: The configuration parameter value (BY_NUMBER or BY_CONTENT)
Line 2: An integer nbLinesV1 for the number of lines in the original file
Next nbLinesV1 lines: The lines of the original file
Next line: An integer nbLinesV2 for the number of lines in the revised file
Next nbLinesV2 lines: The lines of the revised file

Output

If there are no differences you must write No Diffs.

Otherwise, you must write a line for each difference found in alphabetical order.

A difference shall be displayed as follows:
• for a deleted line: DELETE: deleted line
• for an added line: ADD: added line
• for a changed line: CHANGE: original line ---> revised line
• for a moved line: MOVE: original line @:original line number >>> @:revised line number

The alphabetical comparison process shall compare the entire line (including the difference kind).
The line numbers displayed shall be 1-indexed (i.e., the line numbers start at 1, not 0)

Constraints

0 ≤ nbLinesV1, nbLinesV2 ≤ 20
Within a given version of a file, every line will be unique.
The diff tool has to support ADD, DELETE, CHANGE and MOVE differences only.

Example

Input

BY_CONTENT
3
CodinGame is a fun website to learn programming skills.
It supports a large set of programming languages.
The progression path is divided in four parts: development speed, algorithms, optimisation and artificial intelligence.
4
CodinGame is a fun website to learn programming skills.
It supports a large set of programming languages.
The progression path is divided in four parts: development speed, algorithms, optimisation and artificial intelligence.
Some experience points are awarded on tasks achievement

Output

ADD: Some experience points are awarded on tasks achievement

Solve it

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