Submission #336667

#	Time	Username	Problem	Language	Result	Execution time	Memory
336667		jbroeksteeg	Ice Hockey World Championship (CEOI15_bobek)	C++14	100 / 100	687 ms	25148 KiB

bobek

#include <iostream>
#include <climits>
#include <iomanip>
#include <math.h>
#include <numeric>
#include <cassert>
#include <algorithm>
#include <queue>
#include <map>
#include <stack>
#include <set>
#include <vector>
#include <array>
#include <memory>

#define IN(a,b) (a.find(b) != a.end())
#define p(a,b) make_pair(a,b)
#define readVec(a) for (int64_t __i = 0; __i<(int64_t)a.size();__i++){cin>>a[__i];}

// jimjam

template<typename T>
void pMin(T &a, T b) {if (b<a){a=b;}}
template<typename T>
void pMax(T &a, T b) {if (b>a){a=b;}}
template<typename T>
std::ostream& operator<<(std::ostream& os, const std::vector<T>& c);
template<typename A, typename B>
std::ostream& operator<<(std::ostream& os, const std::pair<A,B>& c) {std::cout << "(" << c.first << ", " << c.second << ")";return os;}
template<typename T>
std::ostream& operator<<(std::ostream& os, const std::vector<T>& c) {
	if (c.size() == 0) {os << "{}"; return os;}
	os << "{" << c[0];
	for (int64_t i = 1; i < (int64_t)c.size(); i++) {os <<", "<<c[i];}
	os << "}";
	return os;
}

const int64_t inf = 2e9;

using namespace std;

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

	int64_t n, m; cin >> n >> m;
	vector<int64_t> a(n);
	readVec(a);
	if (n==1) {
		cout << 1+(a[0]<=m) << '\n';
		return 0;
	}

	int64_t mid = n/2;
	vector<int64_t> leftSum;
	for (int64_t mask = 0; mask < 1<<(mid+1); mask++) {
		int64_t su=0;
		for (int64_t i = 0; i <= mid; i++) {
			if (mask & (1<<i)) {
				su += a[i];
			}
		}
		leftSum.push_back(su);
	}
	int64_t rL = mid+1;
	int64_t rSize = n-rL;
	vector<int64_t> rightSum;
	for (int64_t mask = 0; mask < 1<<rSize; mask++) {
		int64_t su=0;
		for (int64_t i = mid+1; i < n; i++) {
			if (mask & (1<<(i-(mid+1)))) {
				su += a[i];
			}
		}
		rightSum.push_back(su);
	}
	int64_t ans=0;
	sort(rightSum.begin(),rightSum.end());
	for (int64_t i: leftSum) {
		auto iter = lower_bound(rightSum.begin(),rightSum.end(), m-i+1);
		ans += distance(rightSum.begin(),iter);
	}
	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