1 #include<stdio.h>
 2 #include<stdlib.h>
 3 #define maxn 30
 4 int min, sum,n;
 5 int a[maxn], b[maxn],c[maxn];
 6 int Min(int a, int b)
 7 {
 8     return a> b ? b:a;
 9 }
10 int dfs(int m)
11 {
12     if (m == n + 1)
13     {
14         int temp = sum;
15         int length = 0;
16         for (int j = 1; j <=n; j++)
17         {
18             if (temp == 0)
19                 break;
20             if (c[j] == 0)
21             {
22                 temp %= a[j];
23                 length++;
24             }
25         }
26         if (temp==0)
27         min = Min(min, length);
28         return 0;
29     }
       //这里利用选择为0，未选为1，方便代码调试时按照二进制运算来看，比较直观
30         c[m] = 0;//用来标记哪些被选了
31         dfs(m + 1);
32         c[m] = 1;//标记未被选
33         dfs(m + 1);
34 }
35 int cmp(const void*a, const void*b)
36 {
37     return *(int *)b - *(int*)a;
38 }
39 int main()
40 {
41     int num;
42     scanf("%d", &num);
43     while (num--)
44     {
45         min= 1000000;
46         scanf("%d%d", &n, &sum);
47         for (int i = 1; i <= n; i++)
48         scanf("%d", &a[i]);
49         qsort(&a[1], n, sizeof(a[1]), cmp);
50         dfs(1);
51         if (min!=1000000)
52         printf("%d\n", min);
53         else printf("-1\n");
54     }
55 }