Poj 1276 Cash Machine

 1 #include <iostream>
 2 #include <cstdio>
 3 using namespace std;
 4 #define N 100003
 5 int c[N],w[N];
 6 int dp[N];
 7 int n, v;
 8 void ZeroOnePack(int cost,int weight)    //01背包
 9 {
10     for(int k=v; k>=cost; k--)
11         dp[k] = max(dp[k],dp[k-cost]+weight);
12 }
13 void CompeletPack(int cost,int weight)    //完全背包
14 {
15     for(int k=cost; k<=v; k++)
16         dp[k] = max(dp[k],dp[k-cost]+weight);
17 }
18 void MultiplePack(int cost,int weight,int amount)    //多重背包
19 {
20     if(cost*amount>=v)
21     {
22         CompeletPack(cost,weight);
23         return;
24     }
25     else
26     {
27         int k=1;
28         while(k<amount)
29         {
30             ZeroOnePack(k*cost,k*weight);
31             amount = amount-k;
32             k=k*2;
33         }
34         ZeroOnePack(amount*cost,amount*weight);
35     }
36 }
37 int main()
38 {
39     int i;
40     while(scanf("%d %d",&v,&n)!=EOF)
41     {
42         int totle = 0;
43         int min = 100002;
44         for(i=0; i<n; i++)
45         {
46             scanf("%d%d",&w[i],&c[i]);    //每种金币的个数和金币面值
47             totle += w[i]*c[i];
48             if(min>c[i])
49                 min = c[i];
50         }
51         if(totle<v) //如果金币的总量小于输入的v，直接将totle输出
52         {
53             printf("%d\n",totle);
54             continue;
55         }
56         if(v<min)//如果v小于金币的最小值，则直接输出0
57         {
58             printf("0\n");
59             continue;
60         }
61         memset(dp,0,sizeof(dp));
62         for (i=0; i<n; i++)
63         {
64             if(w[i]*c[i] == v)
65             {
66                 dp[v] = v;
67                 break;
68             }
69             else
70                 MultiplePack(c[i],c[i],w[i]);//多重背包
71         }
72 
73         printf("%d\n",dp[v]);
74     }
75     return 0;
76 }