Submission #507245

#	Time	Username	Problem	Language	Result	Execution time	Memory
507245		abc864197532	Bootfall (IZhO17_bootfall)	C++17	100 / 100	508 ms	2044 KiB

bootfall

#include <bits/stdc++.h>
using namespace std;
#define lli long long int
#define mp make_pair
#define eb emplace_back
#define pb push_back
#define X first
#define Y second
#define pii pair<int, int>
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
void abc() {cout << endl;}
template <typename T, typename ...U> void abc(T i, U ...j) {
	cout << i << ' ', abc(j...);
}
template <typename T> void printv(T l, T r) {
	for (; l != r; ++l)
		cout << *l << " \n"[l + 1 == r];
}
#define test(x...) abc("[" + string(#x) + "]", x);
const int N = 500 * 500 + 5, C = 23;

bitset <N> dp;

int main () {
	ios::sync_with_stdio(false);
	cin.tie(0);
	int n;
	cin >> n;
	vector <int> a(n);
	int sum = 0;
	dp.flip(0);
	for (int i = 0; i < n; ++i) {
		cin >> a[i];
		sum += a[i];
		dp |= dp << a[i];
	}
	if (sum & 1 || !dp[sum >> 1]) {
		cout << 0 << endl << endl;
	} else {
		vector <int> ans(N, 0);
		for (int i = 0; i < n; i += C) {
			int to = min(i + C, n);
			dp.reset(), dp.flip(0);
			for (int j = 0; j < i; ++j)
				dp |= dp << a[j];
			for (int j = to; j < n; ++j)
				dp |= dp << a[j];
			for (int j = i; j < to; ++j) {
				auto cur = dp;
				for (int k = i; k < to; ++k) if (k ^ j)
					cur |= cur << a[k];
				for (int i = 0; i <= (sum - a[j]) / 2; ++i) if (cur[i])
					ans[abs(sum - a[j] - i - i)]++;
			}
		}
		int cnt = 0;
		for (int i : ans) if (i == n)
			cnt++;
		cout << cnt << endl;
		for (int i = 0; i < N; ++i) if (ans[i] == n)
			cout << i << ' ';
		cout << endl;
	}
}

• Subtask 1: 6 / 6
• Subtask 2: 7 / 7
• Subtask 3: 15 / 15
• Subtask 4: 16 / 16
• Subtask 5: 21 / 21
• Subtask 6: 35 / 35