# Stable Counting Sort

## Description

Sort integers from the fixed range $[0,99]$ in nondecreasing order using stable counting sort.

## Input

The function receives an integer array `a` and its length $n$.

## Output

The same array contains the input values in nondecreasing order.

## Constraints

- $0 \le n \le 100$.
- $0 \le a_i < 100$ for every element.

## Source

Classical counting-sort problem reconstructed from the verified C artifact.