Submission #1091412

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
1091412	2024-09-20T19:35:41 Z	andrei_iorgulescu	Joker (BOI20_joker)	C++14	25 / 100	53 ms	9040 KB

Joker

#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 sz[200005];
bool bad = false;

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);
}

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

/*
4 4 1
2 3
2 1
1 3
3 1
1 4
*/

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}, sz[i] = 1;
    rmin[1] = 1;
    for (int i = m; i >= 1; i--)
    {
        join(u[i], v[i]);
        if (bad)
        {
            rmin[1] = i;
            break;
        }
    }
    //cout << rmin[1] << endl;
    for (int i = 1; i <= q; i++)
    {
        int x, y;
        cin >> x >> y;
        if (y < rmin[x])
            cout << "YES\n";
        else
            cout << "NO\n";
    }
    return 0;
}

///wtfffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff

/**
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	Memory	Grader output
1	Correct	348 KB	Output is correct
2	Correct	348 KB	Output is correct
3	Incorrect	348 KB	Output isn't correct
4	Halted	0 KB	-

Subtask #2
0 / 8.0

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

Subtask #3
25.0 / 25.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	0 ms	348 KB	Output is correct
2	Correct	0 ms	348 KB	Output is correct
3	Correct	43 ms	7508 KB	Output is correct
4	Correct	44 ms	8272 KB	Output is correct
5	Correct	44 ms	8792 KB	Output is correct
6	Correct	42 ms	7556 KB	Output is correct
7	Correct	42 ms	7424 KB	Output is correct
8	Correct	40 ms	6740 KB	Output is correct
9	Correct	41 ms	7504 KB	Output is correct
10	Correct	43 ms	8484 KB	Output is correct
11	Correct	46 ms	7752 KB	Output is correct
12	Correct	44 ms	8788 KB	Output is correct
13	Correct	45 ms	6736 KB	Output is correct
14	Correct	45 ms	7332 KB	Output is correct
15	Correct	53 ms	8276 KB	Output is correct
16	Correct	44 ms	9040 KB	Output is correct