greedy algorithm problem

I really need help to solve a problem using greedy algorithm, I try to search in the net for a code in c, but I find nothing. The kind of problem that I need to solve is fractional or knapsack problem or problem escalation intervals or tree problem Huffman but I need to solve using the greedy algorithm. (Keywords: greedy algorithms, greedy algorithm).
Thank's.

Remember that in general greedy algorithms have this structurte

Code:

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Greedy (E : set of elements)
1. F = Ø
2. while E = Ø 6 do
3.    Greedy choice x ∈ E
4.    E = E − {x}
5.    if F ∪ {x} feasible then
6.          F = F ∪ {x}
7.    end if
8. end while
9. return F

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Hope this helps

Here also pseudocode for discrete problem of knapsack

Code:

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Discrete-Knapsack (X : set of objects , a, c : respective weights and
values, b : weight of knapsack)
 Descending-Sort(ci/ai)
 S = Ø
 for i = 1 to n
    if b ≥ ai
        S = S ∪ {xi}
        b = b − ai
    end if
 end for

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