Compress Consecutive Integer Ranges

# Compress Consecutive Integer Ranges Given an unsorted list of integers, sort the distinct values and render each maximal run of consecutive values as either one integer or start-end. Join rendered runs with commas and no spaces. ### Function Signature ```text compress_ranges(values: list[int]) -> str ``` ### Valid Input Domain Values may be empty and may contain negative, zero, positive, or duplicate 32-bit signed integers. ### Exact Output Semantics Return one canonical string. Duplicate values appear once. Runs are ordered numerically. A run of length one is written as its value; a longer run is written as start-end, including forms such as -3--1. Empty input returns the empty string. ### Constraints - 0 <= values.length <= 200,000. - -2^31 <= values[i] <= 2^31 - 1. - The implementation may sort in place and should avoid an additional set proportional to input size. ### Public Examples #### Example 1 Input: values = [1, 2, 5, 3, 6, 9] Output: "1-3,5-6,9" Sorting yields runs 1 through 3, 5 through 6, and the singleton 9. #### Example 2 Input: values = [-3, -2, -2, -1, 2, 3] Output: "-3--1,2-3" The duplicate -2 is ignored, and negative range punctuation remains unambiguous under the specified format. ### Hints - After sorting, compare each value with the last distinct value rather than the immediately preceding array slot. - Delay emitting a run until a gap appears or the input ends.