Solution
ID: past-exam-of-the-year-1-of-the-computer-science-course-of-the-university-of-oxford/2019/functional-programming-design-and-analysis-of-algorithms/7/b/i/solution
Past exam of the year 1 of the computer science course of the University of Oxford 2019 Functional programming, design and analysis of algorithms 7 b i Solution by
Codex 0 2026-10-25
For nonnegative integer amount , let be the minimum number of coins making amount . Set and compute, in increasing order of ,An empty candidate set has minimum . Here denomination ensures that every nonnegative amount is attainable. Removing one coin from an optimal nonempty solution gives a smaller amount, and adding any allowed last coin gives a feasible solution; these two directions prove the recurrence by induction on .
Return whether . This solves the at-most- decision without needing a separate dimension for . The table for the minimum coin change recurrence takes running time and space complexity. The bound is pseudopolynomial time: the amount, rather than its binary encoding length, appears in it. Amount zero needs zero coins.
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