Cash Machine(多重背包)

http://poj.org/problem?id=1276

 #include <stdio.h>
 #include <string.h>
 const int N=;
 #define Max(a,b) (a)>(b)?(a):(b)
 int dp[N],cash;
 void ZeroOnePack(int cost)//01背包
 {
     for (int i = cash; i >= cost; i--)
     {
         dp[i] = Max(dp[i],dp[i-cost]+cost);
     }
 }
 void ComplexPack(int cost)//完全背包
 {
     for (int i = cost; i <= cash; i++)
     {
         dp[i] = Max(dp[i],dp[i-cost]+cost);
     }
 }
 void MultiplePack(int cnt,int cost)//多重背包
 {
     if (cnt*cost > cash)
         ComplexPack(cost);
     else
     {
         int k = ;
         while(k < cnt)
         {
             ZeroOnePack(k*cost);
             cnt-=k;
             k<<=;
         }
         ZeroOnePack(cnt*cost);
     }
 }
 int main()
 {
     int n,cost[],cnt[];
     while(~scanf("%d %d",&cash,&n))
     {
         for (int i = ; i <= n; i++)
         {
             scanf("%d %d",&cnt[i],&cost[i]);
         }
         memset(dp,,sizeof(dp));
         for (int i = ; i <= n; i++)
         {
             MultiplePack(cnt[i],cost[i]);
         }
         printf("%d\n",dp[cash]);
     }
     return ;
 }