Stringsobits chapter 3.2

跪跪跪,第三章没做几题,已经连跪几天了.好桑心,不过能咋办,不会就看别人的学啊.

同样是暴力搜,别人的剪枝实在是不能太叼.

/*

ID: hubiao cave

PROG: kimbits

LANG: C++

*/




#include<iostream>

#include<fstream>

#include<string>

using namespace std;



int GetOne(int);
 unsigned int N,L,num;
int main()

{

    ifstream fin("kimbits.in");
    ofstream fout("kimbits.out");
    fin>>N>>L>>num;
    unsigned int counter=0;
    unsigned int bnum=0,left;
    unsigned int i=0;
    while(i<(unsigned int )1<<N)
    {
        
        bnum=GetOne(i);
        if(bnum<=L)
        {
            counter++;
        left=L-bnum;
        if(!(i&(1LL<<left)-1))
        {
        if(counter+(1LL<<left)-1<num)
        {
            counter+=(1LL<<left)-1;
            i+=(1LL<<left)-1;
        }
        else
        {
                i=i+num-counter;
                int p=N-1;
                while(p>=0)
                {
                fout<<(i>>p&1);
                p--;
                }
                fout<<endl;
                 return 0;
        }
        }
        }
        else
        {
            i+=(i&(i^(i-1)))-1;
        }

        if(counter==L)
        {
                int p=N-1;
    while(p>=0)
    {
        fout<<(i>>p&1);
        p--;
    }
    fout<<endl;
    return 0;

        }
        i++;
    }

    int p=N-1;
    while(p>=0)
    {
        fout<<(i>>p&1);
        p--;
    }
    fout<<endl;
    return 0;


}



int GetOne(int i)
{
    int counter=0;
    while(i)
    {
        counter++;
        i=i&(i-1);
    }
    return counter;
}