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Submission #498704

# Submission time Handle Problem Language Result Execution time Memory
498704 2021-12-26T07:55:32 Z LittleCube Alternating Current (BOI18_alternating) C++14
32 / 100
 44 ms 5040 KB 
#include <bits/stdc++.h>
#define ll long long
#define pii pair<int, int>
#define pll pair<ll, ll>
#define F first
#define S second
using namespace std;

ll N, M;
vector<pair<int, pii>> v;
int side[100005];

signed main()
{
    ios::sync_with_stdio(0), cin.tie(0);
    cin >> N >> M;
    for (int i = 1; i <= M; i++)
    {
        int a, b;
        cin >> a >> b;
        v.emplace_back(make_pair(i, pii{a, b}));
    }
    if (N <= 15)
    {
        for (int mask = 0; mask < (1 << M); mask++)
        {
            bool valid[2] = {1, 1};
            for (int i = 1; i <= N; i++)
            {
                bool exist[2] = {0, 0};
                for (int j = 0; j < M; j++)
                {
                    pii p = v[j].S;
                    if ((p.F <= p.S && p.F <= i && i <= p.S) || (p.F > p.S && !(p.S < i && i < p.F)))
                        exist[(mask >> j) & 1] = 1;
                }
                valid[0] &= exist[0];
                valid[1] &= exist[1];
            }
            if (valid[0] && valid[1])
            {
                for (int j = 0; j < M; j++)
                    cout << ((mask >> j) & 1);
                cout << '\n';
                return 0;
            }
        }
        cout << "impossible\n";
    }
    else
    {
        int top[3] = {}, idx[3] = {};
        priority_queue<pii> pq[3];
        sort(v.begin(), v.end(), [](pair<int, pii> p1, pair<int, pii> p2)
             { return p1.S.F < p2.S.F; });
        while(top[1] < N || top[2] < N)
        {
            int cur = (top[1] <= top[2] ? 1 : 2);
            while(idx[cur] < M && v[idx[cur]].S.F <= top[cur] + 1)
            {
                pq[cur].push(make_pair(v[idx[cur]].S.S, v[idx[cur]].F));
                idx[cur]++;
            }
            while(!pq[cur].empty() && side[pq[cur].top().S] != 0)
                pq[cur].pop();
            if(pq[cur].empty() || pq[cur].top().F <= top[cur])
            {
                cout << "impossible\n";
                return 0;
            }
            else
            {
                top[cur] = pq[cur].top().F;
                //cout << cur << "use " << pq[cur].top().S << '\n';
                side[pq[cur].top().S] = cur;
                pq[cur].pop();
            }
        }
        for (int i = 1; i <= M; i++)
            cout << side[i] % 2;
        cout << '\n';
    }
}

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 0 ms 204 KB Output is correct
4 Correct 0 ms 204 KB Output is correct
5 Correct 0 ms 204 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
7 Correct 0 ms 204 KB Output is correct
8 Correct 0 ms 204 KB Output is correct
9 Correct 0 ms 204 KB Output is correct
10 Correct 1 ms 204 KB Output is correct
11 Correct 1 ms 204 KB Output is correct
12 Correct 0 ms 204 KB Output is correct
13 Correct 1 ms 204 KB Output is correct
14 Correct 0 ms 204 KB Output is correct
15 Correct 0 ms 204 KB Output is correct
16 Correct 2 ms 204 KB Output is correct
17 Correct 1 ms 204 KB Output is correct
18 Correct 1 ms 204 KB Output is correct
19 Correct 1 ms 204 KB Output is correct
20 Correct 0 ms 204 KB Output is correct
21 Correct 0 ms 204 KB Output is correct
22 Correct 2 ms 204 KB Output is correct
23 Correct 0 ms 204 KB Output is correct
24 Correct 1 ms 204 KB Output is correct
25 Correct 1 ms 204 KB Output is correct
26 Correct 0 ms 204 KB Output is correct
27 Correct 2 ms 204 KB Output is correct
28 Correct 1 ms 204 KB Output is correct
29 Correct 0 ms 204 KB Output is correct
30 Correct 0 ms 204 KB Output is correct
31 Correct 0 ms 204 KB Output is correct
32 Correct 0 ms 204 KB Output is correct
33 Correct 1 ms 204 KB Output is correct
34 Correct 0 ms 204 KB Output is correct
35 Correct 16 ms 204 KB Output is correct
36 Correct 1 ms 204 KB Output is correct
37 Correct 1 ms 204 KB Output is correct
38 Correct 15 ms 316 KB Output is correct
39 Correct 0 ms 204 KB Output is correct
40 Correct 0 ms 204 KB Output is correct

Subtask #2
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 0 ms 204 KB Output is correct
4 Correct 0 ms 204 KB Output is correct
5 Correct 0 ms 204 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
7 Correct 0 ms 204 KB Output is correct
8 Correct 0 ms 204 KB Output is correct
9 Correct 0 ms 204 KB Output is correct
10 Correct 1 ms 204 KB Output is correct
11 Correct 1 ms 204 KB Output is correct
12 Correct 0 ms 204 KB Output is correct
13 Correct 1 ms 204 KB Output is correct
14 Correct 0 ms 204 KB Output is correct
15 Correct 0 ms 204 KB Output is correct
16 Correct 2 ms 204 KB Output is correct
17 Correct 1 ms 204 KB Output is correct
18 Correct 1 ms 204 KB Output is correct
19 Correct 1 ms 204 KB Output is correct
20 Correct 0 ms 204 KB Output is correct
21 Correct 0 ms 204 KB Output is correct
22 Correct 2 ms 204 KB Output is correct
23 Correct 0 ms 204 KB Output is correct
24 Correct 1 ms 204 KB Output is correct
25 Correct 1 ms 204 KB Output is correct
26 Correct 0 ms 204 KB Output is correct
27 Correct 2 ms 204 KB Output is correct
28 Correct 1 ms 204 KB Output is correct
29 Correct 0 ms 204 KB Output is correct
30 Correct 0 ms 204 KB Output is correct
31 Correct 0 ms 204 KB Output is correct
32 Correct 0 ms 204 KB Output is correct
33 Correct 1 ms 204 KB Output is correct
34 Correct 0 ms 204 KB Output is correct
35 Correct 16 ms 204 KB Output is correct
36 Correct 1 ms 204 KB Output is correct
37 Correct 1 ms 204 KB Output is correct
38 Correct 15 ms 316 KB Output is correct
39 Correct 0 ms 204 KB Output is correct
40 Correct 0 ms 204 KB Output is correct
41 Correct 1 ms 204 KB Output is correct
42 Incorrect 1 ms 208 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 1 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 0 ms 204 KB Output is correct
4 Correct 0 ms 204 KB Output is correct
5 Correct 0 ms 204 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
7 Correct 0 ms 204 KB Output is correct
8 Correct 0 ms 204 KB Output is correct
9 Correct 0 ms 204 KB Output is correct
10 Correct 1 ms 204 KB Output is correct
11 Correct 1 ms 204 KB Output is correct
12 Correct 0 ms 204 KB Output is correct
13 Correct 1 ms 204 KB Output is correct
14 Correct 0 ms 204 KB Output is correct
15 Correct 0 ms 204 KB Output is correct
16 Correct 2 ms 204 KB Output is correct
17 Correct 1 ms 204 KB Output is correct
18 Correct 1 ms 204 KB Output is correct
19 Correct 1 ms 204 KB Output is correct
20 Correct 0 ms 204 KB Output is correct
21 Correct 0 ms 204 KB Output is correct
22 Correct 2 ms 204 KB Output is correct
23 Correct 0 ms 204 KB Output is correct
24 Correct 1 ms 204 KB Output is correct
25 Correct 1 ms 204 KB Output is correct
26 Correct 0 ms 204 KB Output is correct
27 Correct 2 ms 204 KB Output is correct
28 Correct 1 ms 204 KB Output is correct
29 Correct 0 ms 204 KB Output is correct
30 Correct 0 ms 204 KB Output is correct
31 Correct 0 ms 204 KB Output is correct
32 Correct 0 ms 204 KB Output is correct
33 Correct 1 ms 204 KB Output is correct
34 Correct 0 ms 204 KB Output is correct
35 Correct 16 ms 204 KB Output is correct
36 Correct 1 ms 204 KB Output is correct
37 Correct 1 ms 204 KB Output is correct
38 Correct 15 ms 316 KB Output is correct
39 Correct 0 ms 204 KB Output is correct
40 Correct 0 ms 204 KB Output is correct
41 Correct 1 ms 204 KB Output is correct
42 Incorrect 1 ms 208 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 23 ms 4112 KB Output is correct
2 Correct 1 ms 332 KB Output is correct
3 Correct 11 ms 1728 KB Output is correct
4 Correct 12 ms 2356 KB Output is correct
5 Correct 44 ms 3880 KB Output is correct
6 Correct 28 ms 3636 KB Output is correct
7 Correct 36 ms 4368 KB Output is correct
8 Correct 2 ms 464 KB Output is correct
9 Correct 1 ms 328 KB Output is correct
10 Correct 43 ms 4000 KB Output is correct
11 Correct 29 ms 3260 KB Output is correct
12 Correct 29 ms 2976 KB Output is correct
13 Correct 1 ms 328 KB Output is correct
14 Correct 1 ms 304 KB Output is correct
15 Correct 35 ms 4668 KB Output is correct
16 Correct 12 ms 2752 KB Output is correct
17 Correct 32 ms 4772 KB Output is correct
18 Correct 36 ms 5040 KB Output is correct
19 Correct 2 ms 464 KB Output is correct
20 Correct 36 ms 3904 KB Output is correct

Subtask #5
0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 0 ms 204 KB Output is correct
4 Correct 0 ms 204 KB Output is correct
5 Correct 0 ms 204 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
7 Correct 0 ms 204 KB Output is correct
8 Correct 0 ms 204 KB Output is correct
9 Correct 0 ms 204 KB Output is correct
10 Correct 1 ms 204 KB Output is correct
11 Correct 1 ms 204 KB Output is correct
12 Correct 0 ms 204 KB Output is correct
13 Correct 1 ms 204 KB Output is correct
14 Correct 0 ms 204 KB Output is correct
15 Correct 0 ms 204 KB Output is correct
16 Correct 2 ms 204 KB Output is correct
17 Correct 1 ms 204 KB Output is correct
18 Correct 1 ms 204 KB Output is correct
19 Correct 1 ms 204 KB Output is correct
20 Correct 0 ms 204 KB Output is correct
21 Correct 0 ms 204 KB Output is correct
22 Correct 2 ms 204 KB Output is correct
23 Correct 0 ms 204 KB Output is correct
24 Correct 1 ms 204 KB Output is correct
25 Correct 1 ms 204 KB Output is correct
26 Correct 0 ms 204 KB Output is correct
27 Correct 2 ms 204 KB Output is correct
28 Correct 1 ms 204 KB Output is correct
29 Correct 0 ms 204 KB Output is correct
30 Correct 0 ms 204 KB Output is correct
31 Correct 0 ms 204 KB Output is correct
32 Correct 0 ms 204 KB Output is correct
33 Correct 1 ms 204 KB Output is correct
34 Correct 0 ms 204 KB Output is correct
35 Correct 16 ms 204 KB Output is correct
36 Correct 1 ms 204 KB Output is correct
37 Correct 1 ms 204 KB Output is correct
38 Correct 15 ms 316 KB Output is correct
39 Correct 0 ms 204 KB Output is correct
40 Correct 0 ms 204 KB Output is correct
41 Correct 1 ms 204 KB Output is correct
42 Incorrect 1 ms 208 KB 'impossible' claimed, but there is a solution
43 Halted 0 ms 0 KB -