Sorting Serial Numbers

Archived question

Try the question in your own editor, then check your output below.

THE QUESTION

Text from the official booklet. Refer to the PDF for original mathematical notation, formatting, and linked input files. Printed samples and inputs are reproduced as published.

Each robot has a unique 4-digit serial number. The greater the number, the more
powerful the robot.
serial_numbers = [4532, 1298, 8765, 2341, 9087, 3456, 7821, 1112, 5678,
4321, 8760, 9080, 1234, 2345, 6789, 4320, 3450, 8761, 9081, 1111, 5671,
6543, 3210, 7654, 8762, 4322, 5679, 9082, 2346, 3457, 1235, 6780, 4323,
2347, 8763, 9083, 5670, 4324, 2348, 3458, 6781, 8764, 9084, 1236, 4325,
2349, 3459, 5672, 6782, 8766, 9085, 1237, 4326, 2340, 3451, 5673, 6783,
8767, 9086, 1238, 4327, 2342, 3452, 5674, 6784, 8768, 9088, 1239, 4328,
2343, 3453, 5675, 6785, 8769, 9089, 1240, 4329, 2344, 3454, 5676, 6786,
8770, 9090, 1241, 4330, 3455, 5677, 6787, 8771, 9091, 1242, 4331, 5678,
6788, 8772, 9092, 1243, 4332, 6789, 8773, 9093, 1244, 4333, 8774, 9094,
1245, 4334, 8775, 9095, 1246]
Sort the given list of serial numbers in ascending order.

CHECK YOUR ANSWER

Try your answer.

The printed count is inaccurate: there are 110 supplied entries. This check uses all of them.

Run your program in your own editor, then paste its output below. This checks the stated output; it does not assess your full program. Practice attempts do not affect competition scores.

Reveal worked answer

Your output

[1111, 1112, 1234, 1235, 1236, 1237, 1238, 1239, 1240, 1241, 1242, 1243, 1244, 1245, 1246, 1298, 2340, 2341, 2342, 2343, 2344, 2345, 2346, 2347, 2348, 2349, 3210, 3450, 3451, 3452, 3453, 3454, 3455, 3456, 3457, 3458, 3459, 4320, 4321, 4322, 4323, 4324, 4325, 4326, 4327, 4328, 4329, 4330, 4331, 4332, 4333, 4334, 4532, 5670, 5671, 5672, 5673, 5674, 5675, 5676, 5677, 5678, 5678, 5679, 6543, 6780, 6781, 6782, 6783, 6784, 6785, 6786, 6787, 6788, 6789, 6789, 7654, 7821, 8760, 8761, 8762, 8763, 8764, 8765, 8766, 8767, 8768, 8769, 8770, 8771, 8772, 8773, 8774, 8775, 9080, 9081, 9082, 9083, 9084, 9085, 9086, 9087, 9088, 9089, 9090, 9091, 9092, 9093, 9094, 9095]

Sort every supplied serial number in ascending order, retaining repeated values.

Source: Girls in Code SEA 2025 Fall Competition, 29 November 2025. Booklet created by Emily Xu and the GIC question authors. Shared for non-commercial educational use with attribution, as permitted in the booklet.