poj1276

多重背包，但由于是bool型，可以使用特殊方法优化效率使得效率与01背包相同

View Code

#include <iostream>

#include <cstdlib>

#include <cstdio>

#include <cstring>

using namespace std;



#define maxn 15

#define maxc 100005



int cash;

int n;

int num[maxn], denomination[maxn];

bool f[maxc];

int used[maxc];



void input()

{

    scanf("%d", &n);

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

        scanf("%d%d", &num[i], &denomination[i]);

}



void work()

{

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

    f[0] = true;

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

    {

        memset(used, 0, sizeof(used));

        for (int j = denomination[i]; j <= cash; j++)

            if (f[j - denomination[i]] && !f[j] && used[j - denomination[i]] < num[i])

            {

                f[j] = true;

                used[j] = used[j - denomination[i]] + 1;

            } 

    }

}



int main()

{

    //freopen("t.txt", "r", stdin);

    while (~scanf("%d", &cash))

    {

        input();

        work();

        for (int i = cash; i >= 0; i--)

            if (f[i])

            {

                printf("%d\n", i);

                break;

            }

    }

    return 0;

}