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Submission #532712

# Submission time Handle Problem Language Result Execution time Memory
532712 2022-03-03T16:47:09 Z fatemetmhr Alternating Current (BOI18_alternating) C++17
32 / 100
 374 ms 9700 KB 
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

#define pb push_back

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());


const int maxn5 = 2e5 + 10;

int a[maxn5], b[maxn5];
bool av[2][maxn5];
int n, m;
bool ty[maxn5];
vector <int> seg[maxn5], ex;

inline void kill(){
	cout << "impossible" << endl;
	exit(0);
}

inline void solve(){
	for(int i = 0; i < m; i++){
		seg[a[i]].pb(i);
	}
	int id1 = -1, id2 = -1;
	for(int i = 0; i < n; i++){
		if(b[id1] < i)
			id1 = -1;
		if(b[id2] < i)
			id2 = -1;
		while(!ex.empty() && b[ex.back()] < i)
			ex.pop_back();
		for(auto u : seg[i])
			ex.pb(u);
		if(id1 == -1){
			if(ex.empty())
				kill();
			id1 = ex.back();
			ty[id1] = true;
			ex.pop_back();
		}
		while(!ex.empty() && b[ex.back()] < i)
			ex.pop_back();
		if(id2 == -1){
			if(ex.empty())
				kill();
			id2 = ex.back();
			ex.pop_back();
		}
	}
	for(int i = 0; i < m; i++)
		cout << ty[i];
	cout << endl;
	exit(0);
}


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

	cin >> n >> m;
	for(int i = 0; i < m; i++){
		cin >> a[i] >> b[i];
		a[i]--;
		b[i]--;
	}

	if(max(n, m) > 20) 
		solve();

	for(int mask = 1; mask < (1 << m) - 1; mask++){
		memset(av, false, sizeof av);
		for(int i = 0; i < m; i++){
			int x = a[i];
			while(true){
				av[(mask >> i)&1][x] = true;
				if(x == b[i])
					break;
				x++;
				if(x == n)
					x = 0;
			}
		}
		bool re = true;
		for(int i = 0; i < n; i++)
			if(!av[0][i] || !av[1][i])
				re = false;
		if(re){
			for(int i = 0; i < m; i++)
				cout << ((mask >> i)&1);
			return cout << endl, 0;
		}
	}
	cout << "impossible" << endl;

}

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 5324 KB Output is correct
2 Correct 3 ms 5324 KB Output is correct
3 Correct 3 ms 5324 KB Output is correct
4 Correct 4 ms 5324 KB Output is correct
5 Correct 3 ms 5324 KB Output is correct
6 Correct 3 ms 5324 KB Output is correct
7 Correct 4 ms 5324 KB Output is correct
8 Correct 4 ms 5324 KB Output is correct
9 Correct 3 ms 5324 KB Output is correct
10 Correct 8 ms 5324 KB Output is correct
11 Correct 4 ms 5324 KB Output is correct
12 Correct 6 ms 5304 KB Output is correct
13 Correct 28 ms 5324 KB Output is correct
14 Correct 3 ms 5324 KB Output is correct
15 Correct 3 ms 5324 KB Output is correct
16 Correct 39 ms 5324 KB Output is correct
17 Correct 7 ms 5324 KB Output is correct
18 Correct 6 ms 5412 KB Output is correct
19 Correct 3 ms 5408 KB Output is correct
20 Correct 3 ms 5324 KB Output is correct
21 Correct 3 ms 5324 KB Output is correct
22 Correct 39 ms 5324 KB Output is correct
23 Correct 3 ms 5324 KB Output is correct
24 Correct 7 ms 5424 KB Output is correct
25 Correct 5 ms 5328 KB Output is correct
26 Correct 4 ms 5324 KB Output is correct
27 Correct 62 ms 5324 KB Output is correct
28 Correct 3 ms 5412 KB Output is correct
29 Correct 4 ms 5408 KB Output is correct
30 Correct 4 ms 5324 KB Output is correct
31 Correct 3 ms 5324 KB Output is correct
32 Correct 3 ms 5408 KB Output is correct
33 Correct 3 ms 5324 KB Output is correct
34 Correct 4 ms 5324 KB Output is correct
35 Correct 374 ms 5408 KB Output is correct
36 Correct 22 ms 5324 KB Output is correct
37 Correct 5 ms 5324 KB Output is correct
38 Correct 322 ms 5400 KB Output is correct
39 Correct 5 ms 5412 KB Output is correct
40 Correct 4 ms 5324 KB Output is correct

Subtask #2
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 5324 KB Output is correct
2 Correct 3 ms 5324 KB Output is correct
3 Correct 3 ms 5324 KB Output is correct
4 Correct 4 ms 5324 KB Output is correct
5 Correct 3 ms 5324 KB Output is correct
6 Correct 3 ms 5324 KB Output is correct
7 Correct 4 ms 5324 KB Output is correct
8 Correct 4 ms 5324 KB Output is correct
9 Correct 3 ms 5324 KB Output is correct
10 Correct 8 ms 5324 KB Output is correct
11 Correct 4 ms 5324 KB Output is correct
12 Correct 6 ms 5304 KB Output is correct
13 Correct 28 ms 5324 KB Output is correct
14 Correct 3 ms 5324 KB Output is correct
15 Correct 3 ms 5324 KB Output is correct
16 Correct 39 ms 5324 KB Output is correct
17 Correct 7 ms 5324 KB Output is correct
18 Correct 6 ms 5412 KB Output is correct
19 Correct 3 ms 5408 KB Output is correct
20 Correct 3 ms 5324 KB Output is correct
21 Correct 3 ms 5324 KB Output is correct
22 Correct 39 ms 5324 KB Output is correct
23 Correct 3 ms 5324 KB Output is correct
24 Correct 7 ms 5424 KB Output is correct
25 Correct 5 ms 5328 KB Output is correct
26 Correct 4 ms 5324 KB Output is correct
27 Correct 62 ms 5324 KB Output is correct
28 Correct 3 ms 5412 KB Output is correct
29 Correct 4 ms 5408 KB Output is correct
30 Correct 4 ms 5324 KB Output is correct
31 Correct 3 ms 5324 KB Output is correct
32 Correct 3 ms 5408 KB Output is correct
33 Correct 3 ms 5324 KB Output is correct
34 Correct 4 ms 5324 KB Output is correct
35 Correct 374 ms 5408 KB Output is correct
36 Correct 22 ms 5324 KB Output is correct
37 Correct 5 ms 5324 KB Output is correct
38 Correct 322 ms 5400 KB Output is correct
39 Correct 5 ms 5412 KB Output is correct
40 Correct 4 ms 5324 KB Output is correct
41 Correct 3 ms 5000 KB Output is correct
42 Incorrect 3 ms 5004 KB 'impossible' claimed, but there is a solution
43 Halted 0 ms 0 KB -

Subtask #3
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 5324 KB Output is correct
2 Correct 3 ms 5324 KB Output is correct
3 Correct 3 ms 5324 KB Output is correct
4 Correct 4 ms 5324 KB Output is correct
5 Correct 3 ms 5324 KB Output is correct
6 Correct 3 ms 5324 KB Output is correct
7 Correct 4 ms 5324 KB Output is correct
8 Correct 4 ms 5324 KB Output is correct
9 Correct 3 ms 5324 KB Output is correct
10 Correct 8 ms 5324 KB Output is correct
11 Correct 4 ms 5324 KB Output is correct
12 Correct 6 ms 5304 KB Output is correct
13 Correct 28 ms 5324 KB Output is correct
14 Correct 3 ms 5324 KB Output is correct
15 Correct 3 ms 5324 KB Output is correct
16 Correct 39 ms 5324 KB Output is correct
17 Correct 7 ms 5324 KB Output is correct
18 Correct 6 ms 5412 KB Output is correct
19 Correct 3 ms 5408 KB Output is correct
20 Correct 3 ms 5324 KB Output is correct
21 Correct 3 ms 5324 KB Output is correct
22 Correct 39 ms 5324 KB Output is correct
23 Correct 3 ms 5324 KB Output is correct
24 Correct 7 ms 5424 KB Output is correct
25 Correct 5 ms 5328 KB Output is correct
26 Correct 4 ms 5324 KB Output is correct
27 Correct 62 ms 5324 KB Output is correct
28 Correct 3 ms 5412 KB Output is correct
29 Correct 4 ms 5408 KB Output is correct
30 Correct 4 ms 5324 KB Output is correct
31 Correct 3 ms 5324 KB Output is correct
32 Correct 3 ms 5408 KB Output is correct
33 Correct 3 ms 5324 KB Output is correct
34 Correct 4 ms 5324 KB Output is correct
35 Correct 374 ms 5408 KB Output is correct
36 Correct 22 ms 5324 KB Output is correct
37 Correct 5 ms 5324 KB Output is correct
38 Correct 322 ms 5400 KB Output is correct
39 Correct 5 ms 5412 KB Output is correct
40 Correct 4 ms 5324 KB Output is correct
41 Correct 3 ms 5000 KB Output is correct
42 Incorrect 3 ms 5004 KB 'impossible' claimed, but there is a solution
43 Halted 0 ms 0 KB -

Subtask #4
19.0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 26 ms 7780 KB Output is correct
2 Correct 3 ms 5020 KB Output is correct
3 Correct 20 ms 7516 KB Output is correct
4 Correct 17 ms 7868 KB Output is correct
5 Correct 43 ms 9236 KB Output is correct
6 Correct 31 ms 9144 KB Output is correct
7 Correct 34 ms 9396 KB Output is correct
8 Correct 5 ms 5168 KB Output is correct
9 Correct 4 ms 5036 KB Output is correct
10 Correct 37 ms 9384 KB Output is correct
11 Correct 35 ms 8560 KB Output is correct
12 Correct 38 ms 9700 KB Output is correct
13 Correct 3 ms 4940 KB Output is correct
14 Correct 3 ms 4940 KB Output is correct
15 Correct 32 ms 8904 KB Output is correct
16 Correct 13 ms 7848 KB Output is correct
17 Correct 34 ms 9408 KB Output is correct
18 Correct 25 ms 8192 KB Output is correct
19 Correct 4 ms 5324 KB Output is correct
20 Correct 39 ms 8636 KB Output is correct

Subtask #5
0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 5324 KB Output is correct
2 Correct 3 ms 5324 KB Output is correct
3 Correct 3 ms 5324 KB Output is correct
4 Correct 4 ms 5324 KB Output is correct
5 Correct 3 ms 5324 KB Output is correct
6 Correct 3 ms 5324 KB Output is correct
7 Correct 4 ms 5324 KB Output is correct
8 Correct 4 ms 5324 KB Output is correct
9 Correct 3 ms 5324 KB Output is correct
10 Correct 8 ms 5324 KB Output is correct
11 Correct 4 ms 5324 KB Output is correct
12 Correct 6 ms 5304 KB Output is correct
13 Correct 28 ms 5324 KB Output is correct
14 Correct 3 ms 5324 KB Output is correct
15 Correct 3 ms 5324 KB Output is correct
16 Correct 39 ms 5324 KB Output is correct
17 Correct 7 ms 5324 KB Output is correct
18 Correct 6 ms 5412 KB Output is correct
19 Correct 3 ms 5408 KB Output is correct
20 Correct 3 ms 5324 KB Output is correct
21 Correct 3 ms 5324 KB Output is correct
22 Correct 39 ms 5324 KB Output is correct
23 Correct 3 ms 5324 KB Output is correct
24 Correct 7 ms 5424 KB Output is correct
25 Correct 5 ms 5328 KB Output is correct
26 Correct 4 ms 5324 KB Output is correct
27 Correct 62 ms 5324 KB Output is correct
28 Correct 3 ms 5412 KB Output is correct
29 Correct 4 ms 5408 KB Output is correct
30 Correct 4 ms 5324 KB Output is correct
31 Correct 3 ms 5324 KB Output is correct
32 Correct 3 ms 5408 KB Output is correct
33 Correct 3 ms 5324 KB Output is correct
34 Correct 4 ms 5324 KB Output is correct
35 Correct 374 ms 5408 KB Output is correct
36 Correct 22 ms 5324 KB Output is correct
37 Correct 5 ms 5324 KB Output is correct
38 Correct 322 ms 5400 KB Output is correct
39 Correct 5 ms 5412 KB Output is correct
40 Correct 4 ms 5324 KB Output is correct
41 Correct 3 ms 5000 KB Output is correct
42 Incorrect 3 ms 5004 KB 'impossible' claimed, but there is a solution
43 Halted 0 ms 0 KB -