/*
第一个多重背包题目 真的不理解二进制优化
*/http://acm.hdu.edu.cn/webcontest/contest_showproblem.php?cid=10594&pid=1001&ojid
以下是用二进制优化的 不会超时
#include<stdio.h>
#include<string.h>
#include<iostream>
#include<algorithm>
using namespace std;
int dp[200000],a[7];
void zeroOne(int weiht,int value,int c)
{
for(int j=c;j>=weiht;j--)
dp[j]=max(dp[j],dp[j-weiht]+value);
}
void complelet(int weight,int value,int c)
{
for(int j=weight;j<=c;j++)
dp[j]=max(dp[j],dp[j-weight]+value);
}
void duoChong(int weight,int value,int count,int c)
{
if(count*value>=c)complelet(weight ,value,c);
else
{
int k=1;
while(k<count)
{
zeroOne(k*weight,k*value,c);
count-=k;
k+=k;
}
zeroOne(count*weight,count*value,c);
}
}
int main()
{
int count=0;
while(1)
{
int sum=0;
for(int i=1; i<=6; i++)
{
scanf("%d",&a[i]);
sum+=a[i]*i;
}
if(sum==0)break;
printf("Collection #%d:
",++count);
if(sum%2==1)
{
printf("Can't be divided.
");
continue;
}
int c=sum/2;
memset(dp,0,sizeof(dp));
for(int i=1; i<=6; i++)
duoChong(i,i,a[i],c);
if(dp[c]==sum/2)printf("Can be divided.
");
else printf("Can't be divided.
");
}
return 0;
}
直接化为01背包计算 超时
#include<stdio.h>
#include<string.h>
#include<iostream>
#include<algorithm>
using namespace std;
int dp[200000],a[7],w[7];
int main()
{
int count=0;
while(1)
{
int sum=0;
for(int i=1; i<=6; i++)
{
scanf("%d",&a[i]);
sum+=a[i]*i;
w[i]=i;
}
if(sum==0)break;
printf("Collection #%d:
",++count);
if(sum%2==1)
{
printf("Can't be divided.
");
continue;
}
int c=sum/2;
memset(dp,0,sizeof(dp));
for(int i=1; i<=6; i++)
for(int k=1; k<=a[i]; k++)//有限个数量（超时）
for(int j=c; j>=w[i]; j--)
dp[j]=max(dp[j],dp[j-w[i]]+w[i]);
printf("sum/2=%d
",dp[sum/2]);
if(dp[c]==sum/2)printf("Can be divided.
");
else printf("Can't be divided.
");
}
return 0;
}
下面是搜索做的 比多重背包快了很多
#include<stdio.h>
#include<string.h>
#include<iostream>
#include<algorithm>
using namespace std;
int op=0;
int mid;
int a[8];
void dfs(int cnt,int sum)
{
if(op)return;
if(sum==mid)
{
op=1;
return ;
}
for(int i=cnt; i>=1; i--)
{
if(a[i])
if(sum+i<=mid)
{
a[i]--;
dfs(i,sum+i);
}
}
}
int main()
{
int count=0;
while(1)
{
int sum=0;
for(int i=1; i<=6; i++)
{
scanf("%d",&a[i]);
sum+=i*a[i];
}
if(sum==0)break;
printf("Collection #%d:
",++count);
if(sum%2==1)
{
printf("Can't be divided.
");
continue;
}
mid=sum/2;
op=0;
dfs(6,0);
if(op)printf("Can be divided.
");
else printf("Can't be divided.
");
}
return 0;
}