5723 - Water Gate Management

http://livearchive.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=3734

解题 ：暴力枚举，二进制枚举状态。。

#include<iostream>
#include<stdio.h>
#include<string.h>
#include<algorithm>
#define inf ~0U>>1
using namespace std;
int n,m;
const int maxn=100000;
struct node0
{
    int f;
    int c;
}node[maxn];
int flow[maxn];
int cost[maxn];
void init()
{
    int mm=1<<n;
    for(int i=1;i<mm;i++)
        for(int j=0;j<n;j++)
            if(i&1<<j)
                flow[i]+=node[j].f,cost[i]+=node[j].c;
}
void solve(int v,int t)
{
    int flage=0;
    int mm=1<<n;
    int temp=inf;
    for(int i=1;i<mm;i++)
        if(flow[i]*t>=v)
            flage=1,temp=min(temp,cost[i]);
    if(flage)
        cout<<temp<<endl;
    else
        cout<<"IMPOSSIBLE"<<endl;
    return ;
}

int main()
{
    while(scanf("%d",&n)!=EOF)
    {
        for(int i=0;i<n;i++)
           scanf("%d%d",&node[i].f,&node[i].c);
        init();
        scanf("%d",&m);
        for(int j=1;j<=m;j++)
        {
            int v,t;
            scanf("%d%d",&v,&t);
            printf("Case %d: ",j);
            solve(v,t);
        }
    }
    return 0;
}