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所选的数比当前的数大的话就失去意义了 所以要保证最小每一步所选的取余的数都不能大于当前被取余的数
数据范围很小 直接暴力dfs即可
#include<cstdio>
#include<cstring>
#include<stack>
#include<vector>
#include<queue>
#include<cmath>
#include<cstdlib>
#include<iostream>
#include<algorithm>
using namespace std;
const int oo = 0x3f3f3f3f;
const int maxn = 1e6+117;
const int mod = 1e9+7;
typedef unsigned long long LL;
typedef double de;
int b[maxn], ans, vis[maxn], n;
int cmp(int a, int b)
{
return a > b;
}
void dfs(int x, int step, int m)
{
if(x == n+1)
{
if(m == 0)
ans = min(ans, step);
return ;
}
for(int i = x; i <= n; i++)
{
if(vis[i] == 0 && b[i] <= m)
{
vis[i] = 1;
dfs(i+1, step+1, m%b[i]);
vis[i] = 0;
}
}
dfs(x+1, step, m);
}
int main()
{
int T, i, a;
scanf("%d", &T);
while(T--)
{
scanf("%d %d", &n, &a);
ans = oo;memset(vis, 0, sizeof(vis));
for(i = 1; i <= n; i++)
scanf("%d", &b[i]);
sort(b+1, b+1+n, cmp);
dfs(1, 0, a);
if(ans != oo) printf("%d\n", ans);
else printf("-1\n");
}
return 0;
}
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原文地址:http://www.cnblogs.com/PersistFaith/p/4958382.html