Correctedness

Knapsack Problem:

Imagine you have a collection of numbers, let’s call this set S (e.g., S = {s₁, s₂, …, sₙ}). You also have a specific target total, T. The challenge is to find if you can pick some numbers from set S that add up to exactly T.

1: “First Available” Strategy

Easily denied by a counter-example:
Assume T=20
S = {19, 10, 10}
The algorithm will pick 19, instead of 10 and 10; the correct answer

2: “Smallest First” Strategy

Also denied:
Assume T= 12
S = {1,3,9}
Will pick 1 then 3 instead of filling the exact sum

3: “Biggest First” Strategy

Denied using the same example used to counter-example Strat No. 1

Efficiency