hdoj1864

平时都是搜索回溯慢,背包快,这道题倒是个特例,背包500ms,搜索0ms。

Problem : 1864 ( 最大报销额 )     Judge Status : Accepted
RunId : 2682097    Language : G++    Author : huwenbiao
Code Render Status : Rendered By HDOJ G++ Code Render Version 0.01 Beta
/***************************************************************\
*Author:Hu Wenbiao
*Created Time: Sun 25 Jul 2010 03:22:16 PM CST
*File Name: main.cpp
*Description:01背包
\***************************************************************/

//*========================*Head File*========================*\\

#include<iostream>
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
/*----------------------*Global Variable*----------------------*/
double
Q,price,a,b,c;
int
f[
3000010],N,m,cost,V;
char
type;
bool
flag;

//*=======================*Main Program*=======================*//
using namespace std;

int
main(){

//freopen("input","r",stdin);
while(scanf("%lf%d",&Q,&N)!=EOF&&N){
V=Q*
100;
memset(f,
0,(1+V)*sizeof(int));
while
(N--){
scanf(
"%d",&m);
a=b=c=
0;
flag=
true;
if
(m==
0)continue;
while
(m--){
scanf(
" %c:%lf",&type,&price);
if
(type==
'A')
a+=price;
else if
(type==
'B')
b+=price;
else if
(type==
'C')
c+=price;
else

flag=
false;
}

if
(a>
600||b>600||c>600||a+b+c>1000)
flag=
false;
if
(!flag)continue;
cost=(a+b+c)*
100;
for
(int v=V;v>=cost;v--)
f[v]=max(f[v],f[v-cost]+cost);
}

double
ans=f[V];
printf(
"%.2lf\n",ans/100);
}
}


posted @ 2010-07-25 16:24  open source  阅读(263)  评论(0编辑  收藏