Uva 624 CD

code：

#include<stdio.h>

#include<stdlib.h>

#include<iostream>

#include<algorithm>

#include<string.h>

#include<vector>

using namespace std;

int p[25],N,k,visit[25],maxn=0;

vector<int> ans,final_;

void back_tracking(int w,int n,int over,int s)

{

    if(w>maxn)

    {

        final_=ans;

        maxn=w;

    }

    if(over>=N || n>=k ) return;

    for(int i=s; i<k; i++)

    {

        if(!visit[i])

        {

            visit[i]=true;

            if(w+p[i]>N) back_tracking(w,n,over+p[i],i);

            else

            {

                ans.push_back(p[i]);

                back_tracking(w+p[i],n+1,over+p[i],i+1);

                ans.pop_back();

            }

            visit[i]=false;

        }

    }

}

int main()

{

    while(cin>>N>>k)

    {

        maxn=0;

        memset(p,0,sizeof(p));

        memset(visit,false,sizeof(visit));

        ans.clear();

        final_.clear();

        for(int i=0; i<k; i++)

        {

            scanf("%d",&p[i]);

        }

        back_tracking(0,0,0,0);

        for(int i=0; i<final_.size(); i++)

        {

            printf("%d ",final_[i]);

        }

        printf("sum:%d\n",maxn);

    }

    return 0;

}