How should I practice Compress Consecutive Integer Ranges?

Start by reading the full statement, solve the visible examples, then compare the pattern against related DocuSign onsite interview problems in FastPrep.

Is Compress Consecutive Integer Ranges associated with DocuSign?

FastPrep tags this as a DocuSign onsite interview coding practice problem when the problem catalog has that company and stage context.

Problem · Array

Compress Consecutive Integer Ranges

Learn this problem

● Easy

DocuSignFULLTIMEONSITE INTERVIEW

Problem statement

Given an unsorted integer array nums, return a compact string describing its distinct values in ascending order.

Sort the values and split them into maximal runs of consecutive integers. Format a run containing at least two distinct values as start-end, format a singleton as its decimal value, and join the pieces with commas and no spaces. Repeated occurrences of a value belong to the same run and appear only once in the result. Return the empty string for an empty array.

Function

compressRanges(nums: int[]) → String

Examples

Example 1

nums = [1,2,5,3,6,9]return = "1-3,5-6,9"

Sorting gives [1,2,3,5,6,9]. The maximal runs are 1 through 3, 5 through 6, and the singleton 9.

Example 2

nums = [1,3,5,7,9]return = "1,3,5,7,9"

No two distinct values are consecutive, so every value is a singleton.

Example 3

nums = [-3,-2,-2,-1,2,3]return = "-3--1,2-3"

The duplicate -2 is ignored. The two maximal runs are -3 through -1 and 2 through 3.

Constraints

0 <= nums.length <= 200000.
Every element fits in a signed 32-bit integer.
The method may reorder nums.
Repeated values are emitted once.