LESSON 379 OF 414 · PROJECTS: COMMAND-LINE TOOLS

CLI Tool: head v3 — Cap n at lines.size in Kotlin

Practice

Same signature as v2, but now n may be larger than the number of lines. If n > lines.size simply return all the lines (don't crash, don't pad). For this version assume n ≥ 0. If n is 0, or there are no lines, the result is the empty string.

Function signature:

fun head(lines: List<String>, n: Int): String

Example:

Input: lines = ["alpha", "beta", "gamma"], n = 10

Output: "alpha\nbeta\ngamma"

When printed:
alpha
beta
gamma

lines.subList(0, n) with n > lines.size throws. So clamp n with minOf(n, lines.size) first.

val end = minOf(n, lines.size)
return lines.subList(0, end).joinToString("\n")

The full solution:

class Solution {
    fun head(lines: List<String>, n: Int): String {
        val end = minOf(n, lines.size)
        return lines.subList(0, end).joinToString("\n")
    }
}

STEP 1 OF 2

Guided

Ctrl + Enter to check

CLI Tool: head v3 — Cap n at lines.size in Kotlin

Head V3 in Kotlin