Submission #259227

#	Time	Username	Problem	Language	Result	Execution time	Memory
259227		vioalbert	Ice Hockey World Championship (CEOI15_bobek)	C++14	100 / 100	293 ms	33476 KiB

bobek

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

const ll N = 45, MAX = 20;
ll n, m, border;
ll a[N];
ll dp1[(1<<MAX)], dp2[(1<<MAX)];
vector<ll> v1, v2;

int main() {
	ios::sync_with_stdio(0); cin.tie(0);
	cin >> n >> m;
	border = (n+1)/2;
	for(int i = 0; i < n; i++) {
		cin >> a[i];
	}
	sort(a, a+n, greater<ll>());

	for(int i = 0; i < border; i++)
		dp1[(1<<i)] = a[i];
	dp1[0] = 0;

	for(ll mask = 0; mask < (1<<border); mask++) {
		if(__builtin_popcount(mask) > 1) {
			int x = mask&(-mask);
			dp1[mask] = dp1[x] + dp1[mask^x];
		}
		if(dp1[mask] <= m) {
			v1.push_back(dp1[mask]);
		}
	
	}

	for(int i = border; i < n; i++)
		dp2[(1<<(i-border))] = a[i];
	dp2[0] = 0;

	for(ll mask = 0; mask < (1<<(n-border)); mask++) {
		if(__builtin_popcount(mask) > 1) {
			int x = mask&(-mask);
			dp2[mask] = dp2[x] + dp2[mask^x];
		}
		if(dp2[mask] <= m) {
			v2.push_back(dp2[mask]);
		}
	}

	sort(v1.begin(), v1.end());
	sort(v2.begin(), v2.end());

	ll ans = 0;
	for(ll x : v1) {
		ll len = upper_bound(v2.begin(), v2.end(), m - x) - v2.begin();
		ans += len;
	}
	cout << ans << '\n';

	return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 10 / 10
• Subtask 10: 10 / 10