Submission #171291

#	Time	Username	Problem	Language	Result	Execution time	Memory
171291		ruler	Alternating Current (BOI18_alternating)	C++14	13 / 100	3022 ms	1272 KiB

alternating

// IOI 2021
#include <bits/stdc++.h>
using namespace std;

#define endl '\n'
#define ends ' '
#define die(x) return cout << x << endl, 0
#define all(v) v.begin(), v.end()
#define sz(x) (int)(x.size())
void debug_out() { cerr << endl; }
template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) { cerr << ends << H; debug_out(T...); }
#define debug(...) cerr << "{" << #__VA_ARGS__ << "}:", debug_out(__VA_ARGS__)
typedef long long ll;
typedef pair<int, int> pii;
const ll INF = 1e9;
const ll MOD = 1e9 + 7;

////////////////////////////////////////////////////////////////////

const int N = 1e5 + 5;

int n, m, L[N], R[N];
bool M[N][2];

string S(int mask) {
	string s = "";
	for (int i = 0; i < m; i++) s += '0' + ((mask >> i) & 1);
	return s;
}

int main() {

	ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);

	cin >> n >> m;
	for (int i = 0; i < m; i++) cin >> L[i] >> R[i], L[i]--, R[i]--;
	for (int mask = 0; mask < (1 << m); mask++) {
		for (int i = 0; i < n; i++) M[i][0] = M[i][1] = false;
		for (int i = 0; i < m; i++) {
			for (int j = L[i]; j != R[i]; j = (j + 1) % n) M[j][(mask >> i) & 1] = true;
			M[R[i]][(mask >> i) & 1] = true;
		}
		bool flag = true;
		for (int i = 0; i < n; i++) flag &= M[i][0] & M[i][1];
		if (flag) die(S(mask));
	}
	cout << "impossible" << endl;

	return 0;
}

• Subtask 1: 13 / 13
• Subtask 2: 0 / 20
• Subtask 3: 0 / 22
• Subtask 4: 0 / 19
• Subtask 5: 0 / 26