POJ 1276 Cash Machine(多重背包)

1: #include <iostream>

2: #include <algorithm>

3: #include <memory.h>

4: using namespace std;

5: const int CASH_SIZE = 100001;

6: const int D_SIZE = 1001;

7: int volume;

8: int f[CASH_SIZE], costArr[D_SIZE], weightArr[D_SIZE], amountArr[D_SIZE];

9: 

10: void ZeroOnePack(int cost, int weight)

11: {

12:     for (int v=volume; v>=cost; v--)

13:         f[v]=max(f[v], f[v-cost]+weight);

14: }

15: 

16: void CompletePack(int cost, int weight, int i)

17: {

18:     for (int v=cost; v<=volume; v++)

19:         f[v]=max(f[v],f[v-costArr[i]]+weightArr[i]);

20: }

21: 

22: void MultiplePack(int cost, int weight, int amount, int i)

23: {

24:     if (cost*amount>=volume)

25:     {

26:         CompletePack(cost, weight, i);

27:         return;

28:     }

29:     int k=1;

30:     while (k<amount)

31:     {

32:         ZeroOnePack(k*cost, k*weight);

33:         amount -= k;

34:         k <<= 1;

35:     }

36:     ZeroOnePack(amount*cost, amount*weight);

37: }

38: 

39: int main()

40: {

41:     int n=0;

42:     while (cin >> volume >> n)

43:     {

44:         memset(f, 0, sizeof(f));

45:         memset(weightArr, 0, sizeof(weightArr));

46:         memset(costArr, 0, sizeof(costArr));

47:         for (int i=0; i<n; i++)

48:         {

49:             cin >> amountArr[i] >> costArr[i];

50:             weightArr[i] = costArr[i];

51:         }

52:         for (int i=0; i<n; i++)

53:         {

54:             MultiplePack(costArr[i], weightArr[i], amountArr[i], i);

55:         }

56:         cout << f[volume] << endl;

57:     }

58:     return 0;

59: }