hdu 1059 多重背包

题意：价值分别为1，2，3，4，5，6的物品个数分别为a[1],a[2],a[3],a[4],a[5],a[6],问能不能分成两堆价值相等的。

解法：转化成多重背包

 #include<stdio.h>
 #include<string.h>
 #include<algorithm>
 #include<iostream>
 using namespace std;

 int dp[];
 int a[];

 int nValue;

 //0-1背包，代价为cost,获得的价值为weight
 void ZeroOnePack(int cost,int weight)
 {
     for(int i=nValue;i>=cost;i--)
       dp[i]=max(dp[i],dp[i-cost]+weight);
 }

 //完全背包，代价为cost,获得的价值为weight
 void CompletePack(int cost,int weight)
 {
     for(int i=cost;i<=nValue;i++)
       dp[i]=max(dp[i],dp[i-cost]+weight);
 }

 //多重背包
 void MultiplePack(int cost,int weight,int amount)
 {
     if(cost*amount>=nValue) CompletePack(cost,weight);
     else
     {
         int k=;
         while(k<amount)
         {
             ZeroOnePack(k*cost,k*weight);
             amount-=k;
             k<<=;
         }
         ZeroOnePack(amount*cost,amount*weight);//这个不要忘记了，经常掉了
     }
 }

 int main()
 {
     int iCase=;
     while()
     {
         iCase++;
         int tol=;
         for(int i=;i<=;i++)
         {
             scanf("%d",&a[i]);
             tol+=i*a[i];
         }
         if(tol==)break;
         printf("Collection #%d:\n",iCase);
         if(tol%!=)
         {
             printf("Can't be divided.\n\n");
             continue;
         }
         else
         {
             nValue=tol/;

         }
         memset(dp,,sizeof(dp));
         for(int i=;i<=;i++)
           MultiplePack(i,i,a[i]);
         if(dp[nValue]==nValue)printf("Can be divided.\n\n");
         else printf("Can't be divided.\n\n");
     }
     return ;
 }