进制 #背包dp #贪心

注意到呈倍数的性质，考虑按照倍数转换进制，贪心的选择小的按顺序选择

// Author: xiaruize
const int INF = 0x3f3f3f3f3f3f3f3f;
const int MOD = 1000000007;
const int N = 2e5 + 10;

int n, m;
int a[N], b[N];
pii s[N];
int cnt[N];
vector<int> vec;
int tot;

bool dec(int x)
{
	if (x > tot)
		return false;
	if (cnt[x])
	{
		cnt[x]--;
		return true;
	}
	if (dec(x + 1))
	{
		cnt[x] += s[x + 1].first / s[x].first;
		cnt[x]--;
		return true;
	}
	return false;
}

void solve()
{
	cin >> n >> m;
	rep(i, 1, n) cin >> a[i];
	rep(i, 1, m) cin >> b[i];
	sort(b + 1, b + m + 1);
	rep(i, 1, m)
	{
		if (b[i] != s[tot].first)
			s[++tot].first = b[i];
		s[tot].second++;
	}
	per(i, tot, 1)
	{
		rep(j, 1, n)
		{
			cnt[i] += a[j] / s[i].first;
			a[j] %= s[i].first;
		}
	}
	int res = 0;
	rep(i, 1, tot)
	{
		rep(j, 1, s[i].second)
		{
			if (!dec(i))
			{
				cout << res << endl;
				return;
			}
			res++;
		}
	}
	cout << res << endl;
}

#ifndef ONLINE_JUDGE
bool end_of_memory_use;
#endif

signed main()
{
	// freopen(".in","r",stdin);
	// freopen(".out","w",stdout);
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	int testcase = 1;
	// cin >> testcase;
	while (testcase--)
		solve();
#ifndef ONLINE_JUDGE
	cerr << "Memory use:" << (&end_of_memory_use - &start_of_memory_use) / 1024.0 / 1024.0 << "MiB" << endl;
	cerr << "Time use:" << (double)clock() / CLOCKS_PER_SEC * 1000.0 << "ms" << endl;
#endif
	return 0;
}