hdu 1276 多重背包

 1 #include<cstdio>
 2 #include<iostream>
 3 #include<algorithm>
 4 #include<cstring>
 5 #include<cmath>
 6 #include<queue>
 7 using namespace std;
 8 const int maxn=100005;
 9 int n,m,t;
10 int dp[maxn],w[maxn],v[maxn];
11 int nValue;
12 //0-1背包，代价为cost,获得的价值为weight
13 void ZeroOnePack(int cost,int weight)
14 {
15     for(int i=nValue;i>=cost;i--)
16       dp[i]=max(dp[i],dp[i-cost]+weight);
17 }
18 
19 //完全背包，代价为cost,获得的价值为weight
20 void CompletePack(int cost,int weight)
21 {
22     for(int i=cost;i<=nValue;i++)
23       dp[i]=max(dp[i],dp[i-cost]+weight);
24 }
25 
26 //多重背包
27 void MultiplePack(int cost,int weight,int amount)
28 {
29     if(cost*amount>=nValue) CompletePack(cost,weight);
30     else
31     {
32         int k=1;
33         while(k<amount)
34         {
35             ZeroOnePack(k*cost,k*weight);
36             amount-=k;
37             k<<=1;
38         }
39         ZeroOnePack(amount*cost,amount*weight);//这个不要忘记了，经常掉了
40     }
41 }
42 int main()
43 {
44     int i,j,k;
45     #ifndef ONLINE_JUDGE
46     freopen("1.in","r",stdin);
47     #endif
48     while(scanf("%d%d",&nValue,&n)!=EOF)
49     {
50         for(i=0;i<n;i++)
51         {
52             scanf("%d%d",&w[i],&v[i]);
53         }
54         memset(dp,0,sizeof(dp));
55         for(i=0;i<n;i++)
56         {
57             MultiplePack(v[i],v[i],w[i]);
58         }
59         printf("%d\n",dp[nValue]);
60     }
61 }