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Submission #1113627

# Submission time Handle Problem Language Result Execution time Memory
1113627 2024-11-16T21:00:32 Z ortsac Alternating Current (BOI18_alternating) C++17
19 / 100
 64 ms 6764 KB 
#include <bits/stdc++.h>

using namespace std;

#define pii pair<int, int>
#define fr first
#define se second
#define t(i) ((int) s[i].size())

const int MAXN = 1e5 + 10;
vector<pii> s[MAXN];

int32_t main() {
    int n, m;
    cin >> n >> m;
    for (int i = 0; i < m; i++) {
        int a, b;
        cin >> a >> b;
        s[a].push_back({b, i});
    }
    for (int i = 1; i <= n; i++) {
        sort(s[i].begin(), s[i].end());
        reverse(s[i].begin(), s[i].end());
        while (t(i) > 2) s[i].pop_back();
    }
    vector<int> ans(m);
    int zTill = -1, oTill = -1;
    for (int i = 1; i <= n; i++) {
        int need = 0;
        if (zTill < i) {
            zTill = -1;
            need++;
        }
        if (oTill < i) {
            oTill = -1;
            need++;
        }
        if (need > t(i)) {
            cout << "impossible\n";
            return 0;
        }
        if (t(i) == 1) {
            if (oTill <= zTill) {
                oTill = max(oTill, s[i][0].fr);
                ans[s[i][0].se] = 0;
            } else {
                zTill = max(zTill, s[i][0].fr);
                ans[s[i][0].se] = 1;
            }
        } else if (t(i) == 2) {
            if (oTill <= zTill) {
                oTill = max(oTill, s[i][0].fr);
                ans[s[i][0].se] = 0;
                zTill = max(zTill, s[i][1].fr);
                ans[s[i][1].se] = 1;
            } else {
                zTill = max(zTill, s[i][0].fr);
                ans[s[i][0].se] = 1;
                oTill = max(oTill, s[i][1].fr);
                ans[s[i][1].se] = 0;
            }
        }
    }
    for (auto u : ans) cout << u;
    cout << "\n";
}

Subtask #1
0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2640 KB Output is correct
2 Correct 1 ms 2640 KB Output is correct
3 Incorrect 1 ms 2640 KB 'impossible' claimed, but there is a solution
4 Halted 0 ms 0 KB -

Subtask #2
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2640 KB Output is correct
2 Correct 1 ms 2640 KB Output is correct
3 Incorrect 1 ms 2640 KB 'impossible' claimed, but there is a solution
4 Halted 0 ms 0 KB -

Subtask #3
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2640 KB Output is correct
2 Correct 1 ms 2640 KB Output is correct
3 Incorrect 1 ms 2640 KB 'impossible' claimed, but there is a solution
4 Halted 0 ms 0 KB -

Subtask #4
19.0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 37 ms 3944 KB Output is correct
2 Correct 2 ms 2640 KB Output is correct
3 Correct 26 ms 4424 KB Output is correct
4 Correct 23 ms 5080 KB Output is correct
5 Correct 46 ms 5288 KB Output is correct
6 Correct 46 ms 5192 KB Output is correct
7 Correct 49 ms 6392 KB Output is correct
8 Correct 3 ms 2896 KB Output is correct
9 Correct 2 ms 2640 KB Output is correct
10 Correct 64 ms 6524 KB Output is correct
11 Correct 38 ms 5448 KB Output is correct
12 Correct 41 ms 6764 KB Output is correct
13 Correct 3 ms 2640 KB Output is correct
14 Correct 2 ms 2636 KB Output is correct
15 Correct 50 ms 5748 KB Output is correct
16 Correct 23 ms 5108 KB Output is correct
17 Correct 54 ms 6216 KB Output is correct
18 Correct 40 ms 5448 KB Output is correct
19 Correct 5 ms 2896 KB Output is correct
20 Correct 41 ms 5968 KB Output is correct

Subtask #5
0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2640 KB Output is correct
2 Correct 1 ms 2640 KB Output is correct
3 Incorrect 1 ms 2640 KB 'impossible' claimed, but there is a solution
4 Halted 0 ms 0 KB -