Submission #118763

#	Time	Username	Problem	Language	Result	Execution time	Memory
118763		silxikys	Ice Hockey World Championship (CEOI15_bobek)	C++14	40 / 100	1061 ms	165028 KiB

bobek

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

const int maxn = 40;

struct SegDyn
{
	ll s, e, m; //represents range [s,e]
	SegDyn *l, *r;
	int sum; //sum for this interval
	SegDyn(ll _s, ll _e) {
		s = _s;
		e = _e;
		m = (s+e)/2;
		l = NULL;
		r = NULL;
		sum = 0;
	}

	void prepareL() { if (l == NULL) l = new SegDyn(s,m); }
	void prepareR() { if (r == NULL) r = new SegDyn(m+1,e); }

	void pull() {
		sum = 0;
		if (l) sum += l->sum;
		if (r) sum += r->sum;
	}

	void add(ll idx, int del) { //a[idx] += del
		//cout << s << ' ' << e << '\n';
		if (s == e && s == idx) {
			//at the node, stop
			sum += del;
			return;
		}
		if (idx <= m) {
			prepareL();
			assert(l);
			l->add(idx,del);
		}
		else {
			prepareR();
			r->add(idx,del);
		}
		pull(); //updates current node based on the children
	}

	int getsum(ll se, ll en) {
		if (se <= s && e <= en) return sum;
		int res = 0;
		if (l && se <= m) res += l->getsum(se,en);
		if (r && en > m) res += r->getsum(se,en);
		return res;	
	}
};

int N, M;
ll A[maxn], B[maxn];

int main()
{
	cin >> N >> M;
	int split = N/2;
	for (int i = 0; i < split; i++) {
		cin >> A[i];
	}
    for (int i = split; i < N; i++) {
        cin >> B[i-split];
    }
	SegDyn *root = new SegDyn(0,1e18+5);
	for (int i = 0; i < (1<<split); i++) {
        ll total = 0;
        for (int j = 0; j < split; j++) {
            if (i & (1<<j)) total += A[j];
        }
        root->add(total,1);
    }

    ll ans = 0;
    for (int i = 0; i < (1<<(N-split)); i++) {
        ll total = 0;
        for (int j = 0; j < N-split; j++) {
            if (i & (1<<j)) total += B[j];
        }
        if (total <= M) {
            ans += root->getsum(0,M-total);
        }
    }
    cout << ans << '\n';
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 0 / 10
• Subtask 4: 0 / 10
• Subtask 5: 0 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 10
• Subtask 10: 0 / 10