p1460 Healthy Holsteins

列举所有的子集找最优就行。

#include <iostream>
#include <cstdio>
#include <cmath>
#include <algorithm>
#include <vector>
#include <iomanip>
#include <cstring>
#include <map>
#include <queue>
#include <set>
#include <cassert>
#include <stack>
#define mkp make_pair
using namespace std;
const double EPS=1e-8;
typedef long long lon;
const lon SZ=30,INF=0x7FFFFFFF;
int v[SZ],arr[SZ][SZ];

inline int lowbit(int x)
{
    return x&-x;
}

int getdgt(int x)
{
    int res=0;
    for(;x;x-=lowbit(x),++res);
    return res;
}

bool chk(int x,int n)
{
    int tmp[SZ];
    memset(tmp,0,sizeof(tmp));
    for(int i=0;i<31;++i)
    {
        if(x&(1<<i))
        {
            for(int j=0;j<n;++j)
            {
                tmp[j]+=arr[i][j];
            }
        }
    }
    for(int j=0;j<n;++j)
    {
        if(tmp[j]<v[j])return 0;
    }
    return 1;
}

int main()
{
    std::ios::sync_with_stdio(0);
    //freopen("d:\\1.txt","r",stdin);
    lon casenum;
    //cin>>casenum;
    //for(lon time=1;time<=casenum;++time)
    {
        int n;
        cin>>n;
        for(int i=0;i<n;++i)cin>>v[i];
        int m;
        cin>>m;
        for(int i=0;i<m;++i)
        {
            for(int j=0;j<n;++j)
            {
                cin>>arr[i][j];
            }
        }
        int mind=INF,res=0;
        for(int i=0;i<(1<<m);++i)
        {
            if(getdgt(i)<mind&&chk(i,n))
            {
                mind=getdgt(i);
                res=i;
            }
        }
        cout<<mind;
        for(int i=0;i<31;++i)
        {
            if(res&(1<<i))cout<<" "<<i+1;
        }
        cout<<endl;
    }
    return 0;
}