poj 1011

参考原po ： http://blog.youkuaiyun.com/lyy289065406/article/details/6647960

#include<iostream>  
#include<map>
#include<string>   
#include<algorithm>  
#include<fstream>
#include<cmath>  
#include<vector>
#include<queue>
#include<map>
#include<math.h>
using namespace std;  
#define lch(i) ((i)<<1)  
#define rch(i) ((i)<<1|1)  
#define sqr(i) ((i)*(i))  
#define pii pair<int,int>  
#define mp make_pair  
#define FOR(i,b,e) for(int i=b;i<=e;i++)  
#define FORE(i,b,e) for(int i=b;i>=e;i--)  
#define ms(a)   memset(a,0,sizeof(a))  
const int maxnum =21252;
const  int  mod = 10007;
int n,m;
int ssum,st;
int vec[64];
bool visit[64];


bool dfs(int di,int sum,int lastp,int num){
	if(num==n)
		return true;
	int unfit=0;
	FORE(i,lastp-1,0){
		if(visit[i]||vec[i]==unfit)continue;
		visit[i]=1;
		if(vec[i]+sum<di){
			if(dfs(di,sum+vec[i],i,num+1)){
				return true;
			}
		}
		else if(vec[i]+sum==di){
			unfit=0;
			if(dfs(di,0,n,num+1))//vec[i]灵活度最低，留给其他棍子灵活度最高也失败，剩下方案也失败
				return true;
			/*else{
				visit[i]=0;
				return false;
			}*/
		}
		unfit = vec[i];
		visit[i]=0;
		if(sum==0)break;
	}
	return false;
}


int cmp(const void* a,const void* b){
	return *(int*)a-*(int*)b;
}
//


int main()    
{  
#ifdef _DEBUG_
	fstream fin("G:/1.txt");
#else
#define fin cin
#endif
	for(;;){
		fin>>n;
		if(!n)break;
		ssum=st=0;
		ms(vec);
		ms(visit);
		FOR(i,0,n-1){
			fin>>vec[i];
			ssum+=vec[i];
		}
		qsort(vec,n,sizeof(int),cmp);
		int flag=0;
		for(int i=vec[n-1];i<=ssum-i;i++){
			
			if(ssum%i==0){
				if(i>=st&&dfs(i,0,n,0)){
					printf("%d\n",i);
					flag=1;
					break;
				}
				
			}
		}
		if(!flag)
			printf("%d\n",ssum);
	}
	return 0;
}