Sticks(Central Europe 1995)

Description

George took sticks of the same length and cut them randomly until all parts became at most 50 units long. Now he wants to return sticks to the original state, but he forgot how many sticks he had originally and how long they were originally. Please help him and design a program which computes the smallest possible original length of those sticks. All lengths expressed in units are integers greater than zero.

Input

The input contains blocks of 2 lines. The first line contains the number of sticks parts after cutting, there are at most 64 sticks. The second line contains the lengths of those parts separated by the space. The last line of the file contains zero.

Output

The output should contains the smallest possible length of original sticks, one per line.

Sample Input

9
5 2 1 5 2 1 5 2 1
4
1 2 3 4
0

Sample Output

6

5

解题关键：两个重要剪枝，1.当回来时没有用上最大的值时肯定组合失败（最大数筛） 2.当失败回来时回溯到上一组，同时有一个大块可以匹配，那么后面的元素不需要再考虑，因为此时即使后面有能够匹配的也是不成立的情况。

#include
#include
#include
#include
#include

using namespace std;

int n;
int s[100];
int vis[100];
int ok;

void dfs(int len,int sum,int le,int N,int r)
{
    if(le==N)
    {
        ok=1;
        return ;
    }
    if(sum==len)
    {
        dfs(len,0,le+1,N,0);
    }

    for(int i=r;ib;
}

int main()
{
    while(scanf("%d",&n)!=EOF&&n)
    {
        int sum=0;
        for(int i=0;i