随机化算法之四

#include<iostream>        //随机化算法  poj 2454
#include<algorithm>
#include<vector>
using namespace std;
struct node
{
    int num;int idx;
    bool operator<(const node& o)
    {
        return num<o.num;
    }
}data[200];
int ans[200];
int main()
{
    int k;
    cin>>k;
    for(int i=1;i<=3*k;++i)
    {
        cin>>data[i].num;
        data[i].idx=i;
    }
    sort(data+1,data+3*k+1);
    int s=0;
    for(int i=k+1;i<=3*k;++i)
        s+=data[i].num;
    for(int i=1;i<=k;++i)
        cout<<data[i].idx<<endl;
    while(1)
    {
        int sum=0,c=0,d;
        memset(ans,0,sizeof(ans));
        while(c<k)
        {
            d=rand()%(2*k)+k+1;
            if(ans[d]==1)
                continue;
            c++;
            ans[d]=1;
            sum+=data[d].num;
        }
        if(s-sum>k*500&&sum>k*500)
        {
            for(int i=k+1;i<=3*k;++i)
                if(ans[i]==1)
                    cout<<data[i].idx<<endl;
            for(int i=k+1;i<=3*k;++i)
                if(ans[i]==0)
                    cout<<data[i].idx<<endl;
            break;
        }
    }
    return 0;
}