hdu2191 悼念512汶川大地震 ——多重背包

link:http://acm.hdu.edu.cn/showproblem.php?pid=2191

最简单的那种

 #include <iostream>
 #include <cstdio>
 #include <cstdlib>
 #include <cstring>
 #include <cmath>
 #include <cctype>
 #include <algorithm>
 #include <queue>
 #include <deque>
 #include <queue>
 #include <list>
 #include <map>
 #include <set>
 #include <vector>
 #include <utility>
 #include <functional>
 #include <fstream>
 #include <iomanip>
 #include <sstream>
 #include <numeric>
 #include <cassert>
 #include <ctime>
 #include <iterator>
 const int INF = 0x3f3f3f3f;
 const int dir[][] = {{-,},{,},{,-},{,},{-,-},{-,},{,-},{,}};
 using namespace std;
 int n, V, t, f[], c[], w[], m[];
 void zeropack(int c, int w)
 {
     for (int v=V; v>=c; --v)
     {
         f[v]=max(f[v],f[v-c]+w);
     }
     return;
 }
 void completepack(int c, int w)
 {
     for (int v=c;v<=V;++v)
         f[v]=max(f[v],f[v-c]+w);
     return;
 }
 void multipack(int c, int w, int m)
 {
     if (c*m >= V)
     {
         completepack(c,w); return;
     }
     int k=;
     while (k<m)
     {
         zeropack(c*k,w*k); m-=k; k*=;
     }
     zeropack(c*m,w*m);
     return;
 }
 int main(void)
 {
     ios::sync_with_stdio(false);
     #ifndef ONLINE_JUDGE
     freopen("in.txt", "r", stdin);
     #endif // ONLINE_JUDGE
     int t; cin>>t;
     while (t--)
     {
         cin>>V>>n;
         for (int i=;i<n;++i) cin>>c[i]>>w[i]>>m[i];
         memset(f,,sizeof(f));
         for (int i=;i<n;++i)
         {
             multipack(c[i],w[i],m[i]);
         }
         cout<<f[V]<<endl;
     }
     return ;
 }

其实这种动态规划题目还是要注意初始化，想想问什么这样初始化。