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Submission #1091396

# Submission time Handle Problem Language Result Execution time Memory
1091396 2024-09-20T18:51:36 Z andrei_iorgulescu Joker (BOI20_joker) C++14
0 / 100
 40 ms 3408 KB 
#include <bits/stdc++.h>

using namespace std;

int n, m, q;
int u[200005], v[200005];
int rmin[200005];

pair<int, int> t[200005];
int cnt_bad;

pair<int, int> par(int x)
{
    int s1 = 0;
    while (t[x].first != x)
    {
        s1 += t[x].second;
        x = t[x].first;
    }
    return make_pair(x, s1 % 2);
}

void join(int idx, int x, int y)
{
    pair<int,int> p1 = par(x);
    pair<int,int> p2 = par(y);
    if (p1.first != p2.first)
    {
        t[p2.first] = make_pair(p1.first, (1 + p1.second + p2.second) % 2);
    }
    else
    {
        if (p1.second == p2.second)
            cnt_bad++;
    }
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    cin >> n >> m >> q;
    for (int i = 1; i <= m; i++)
        cin >> u[i] >> v[i];
    for (int i = 1; i <= n; i++)
        t[i] = {i, 0};
    rmin[1] = 1;
    for (int i = m; i >= 1; i--)
    {
        join(i, u[i], v[i]);
        if (cnt_bad != 0)
        {
            rmin[1] = i + 1;
            break;
        }
    }
    for (int i = 1; i <= q; i++)
    {
        int x, y;
        cin >> x >> y;
        assert(x <= y);
        if (rmin[x] > y)
            cout << "YES\n";
        else
            cout << "NO\n";
    }
    return 0;
}

/**
deci teoretic daca bag elementele de la 1 la N, apoi fac two pointers-ul, o sa cam am queue-like undoing pe DSU, pe care tin si ceva de bipartit
**/

Subtask #1
0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Incorrect 0 ms 348 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #2
0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Incorrect 0 ms 348 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #3
0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Incorrect 40 ms 3408 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #4
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Incorrect 0 ms 348 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #5
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Incorrect 0 ms 348 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #6
0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Incorrect 0 ms 348 KB Output isn't correct
4 Halted 0 ms 0 KB -