LESSON 393 OF 413 · PROJECTS: COMMAND-LINE TOOLS

CLI Tool: sort v2 — Reverse (Descending) Sort in C#

Practice

Build the next version of the Unix sort command, this time with the -r flag baked in. Given a list of lines, return them sorted in descending order by character code (the exact reverse of v1's order, like LC_ALL=C sort -r: lowercase letters come before uppercase ones), joined by newline characters (\n). Duplicates are all kept. If the list is empty, return the empty string.

Function signature:

public string SortLines(List<string> lines)

Example:

Input: lines = ["banana", "apple", "cherry"]

Output: "cherry\nbanana\napple"

When printed:
cherry
banana
apple

Sort with a comparator that compares in reverse, e.g. string.Compare(b, a, StringComparison.Ordinal), then combine with string.Join("\n", ...).

The full solution:

class Solution {
    public string SortLines(List<string> lines) {
        List<string> sortedLines = new List<string>(lines);
        sortedLines.Sort((a, b) => string.Compare(b, a, StringComparison.Ordinal));
        return string.Join("\n", sortedLines);
    }
}

STEP 1 OF 3

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CLI Tool: sort v2 — Reverse (Descending) Sort in C#

Sort V2 in C#