Greedy optimality for one-plus-power-of-two coins
ID: greedy-optimality-for-one-plus-power-of-two-coins
For denominations and with , greedy minimizes coin count. Among optimal representations choose a lexicographically maximal descending denomination-count vector. Two unit coins can be replaced by one two; two below the largest can be replaced by without increasing count but improving that vector. Thus all smaller denominations occur at most once. For the coins below , write their value as , where is their count and is the sum of their distinct power-of-two parts. If , one and units use coins, contradicting optimality. Therefore the residual below each denomination is smaller than it, forcing precisely the greedy quotients.
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