Bottom-up dynamic programming. dp[i] = minimum coins to make
amount i.
let dp = Array.make (target + 1) (target + 1) in (* sentinel *)
dp.(0) <- 0;
for i = 1 to target do
List.iter (fun c ->
if c <= i && dp.(i - c) + 1 < dp.(i) then
dp.(i) <- dp.(i - c) + 1
) coins
done
Sentinel 'target + 1' means impossible — any real solution uses at
most 'target' coins.
coin_change [1; 5; 10; 25] 67 = 6 (= 25+25+10+5+1+1)
Exercises Array.make + arr.(i) + arr.(i) <- v + nested
for/List.iter + guard 'c <= i'.
47 baseline programs total.