Submission #204468

#	Time	Username	Problem	Language	Result	Execution time	Memory
204468		staniewzki	Ice Hockey World Championship (CEOI15_bobek)	C++14	100 / 100	569 ms	8788 KiB

bobek

#include<bits/stdc++.h>
using namespace std;
 
ostream& operator<<(ostream &out, string str) {
	for(char c : str) out << c;
	return out;
}
 
template<class L, class R> ostream& operator<<(ostream &out, pair<L, R> p) {
	return out << "(" << p.first << ", " << p.second << ")";
}
 
template<class T> auto operator<<(ostream &out, T a) -> decltype(a.begin(), out) {
	out << "{";
	for(auto it = a.begin(); it != a.end(); it = next(it))
		out << (it != a.begin() ? ", " : "") << *it;
	return out << "}";
}
 
void dump() { cerr << "\n"; }
template<class T, class... Ts> void dump(T a, Ts... x) {
	cerr << a << ", ";
	dump(x...);
}
 
#ifdef DEBUG
#  define debug(...) cerr << "[" #__VA_ARGS__ "]: ", dump(__VA_ARGS__)
#else
#  define debug(...) false
#endif
 
#define REP(i, n) for(int i = 0; i < n; i++)
#define FOR(i, a, b) for(int i = a; i <= b; i++)
#define ST first
#define ND second
 
template<class T> int size(T && a) { return a.size(); }
 
using LL = long long;
using PII = pair<int, int>;

int main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);

	int n;
	LL m;
	cin >> n >> m;
	vector<LL> a(n);
	REP(i, n) cin >> a[i];

	vector<LL> left;
	REP(i, (1 << (n / 2))) {
		LL sum = 0;
		REP(j, n / 2) {
			if(i & (1 << j))
				sum += a[j];
		}
		left.emplace_back(sum);
	}
	sort(left.begin(), left.end());

	LL ans = 0;
	REP(i, (1 << ((n + 1) / 2))) {
		LL sum = 0;
		FOR(j, n / 2, n - 1) {
			if(i & (1 << (j - n / 2))) 
				sum += a[j];
		}
		auto it = upper_bound(left.begin(), left.end(), m - sum);
		ans += distance(left.begin(), it);
	}

	cout << ans << "\n";
}

• 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