题目链接:
http://acm.hdu.edu.cn/showproblem.php?pid=5527
题意&题解:
感觉自己真是弱啊,自己想的贪心是错的,根本没想到20,50的特判,╮(╯▽╰)╭
附我參考的聚聚的题解:
http://blog.csdn.net/snowy_smile/article/details/49592521
代码:
(差点儿和那位聚聚的一样。ORZ)
#include<iostream>
#include<algorithm>
#include<stdio.h>
#include<string.h>
using namespace std;
int val[11]={0,1,5,10,20,50,100,200,500,1000,2000};
int x,T,p,num[11],vis[11],use[11];
int ans=-1;
long long sum;
int solve()
{
memset(use,0,sizeof(use));
if (vis[5]>num[5] || vis[8]>num[8]) return 0;
long long tmp=vis[5]*val[5]+vis[8]*val[8];
int tmpn=vis[5]+vis[8];
for (int i=1;i<=10;i++)
{
if (vis[i]==-1)
{
tmp+=num[i]*val[i];
tmpn+=num[i];
use[i]=num[i];
}
else
{
use[i]=num[i]-vis[i];
if (use[i]%2==1) use[i]--;
tmpn+=use[i];
tmp+=use[i]*val[i];
}
if (tmp>=x)
{
long long chao=tmp-x;
for (int j=i;j>=1;j--)
{
if (vis[j]==-1)
{
long long tui=min((long long)use[j],chao/val[j]);
tmpn-=tui;
chao-=tui*val[j];
}
else
{
long long tui=min((long long)use[j],chao/val[j]);
if (tui%2==1) tui--;
tmpn-=tui;
chao-=tui*val[j];
}
if (chao==0)
{
ans=max(ans,tmpn);
return 0;
}
}
return 0;
}
}
}
int main()
{
scanf("%d",&T);
while(T--)
{
scanf("%d",&x);
memset(vis,-1,sizeof(vis));
for (int i=1;i<=10;i++)
{
scanf("%d",&num[i]);
sum+=num[i]*val[i];
}
if (sum<x)
{
printf("-1\n");
continue;
}
ans=-1;
vis[5]=0,vis[8]=0; solve();
vis[5]=1,vis[8]=1; solve();
vis[5]=1,vis[8]=0; solve();
vis[5]=0,vis[8]=1; solve();
printf("%d\n",ans);
}
}