Submission #1091421

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
1091421	2024-09-20T19:52:09 Z	andrei_iorgulescu	Joker (BOI20_joker)	C++14	25 / 100	48 ms	9044 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 bip[200005];
int cnt_bad;
int curi;

struct ura
{
    int tip;///0 pentru p1.first != p2.first, 1 pentru celalalt
    int idx = 0, x = 0, y = 0;
    bool bipant = false;
};

vector<ura> op;

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

void join(int idx, int x, int y)
{
    //cout << idx << ' ' << x << ' ' << y << endl;
    pair<int,int> p1 = par(x);
    pair<int,int> p2 = par(y);
    //cout << x << ' ' << y << endl;
    if (p1.first != p2.first)
    {
        if (sz[p1.first] < sz[p2.first])
            swap(p1, p2);
        //cout << "c1" << endl;
        t[p2.first] = {p1.first, (1 + p1.second + p2.second) % 2};
        sz[p1.first] += sz[p2.first];
        //sz[x] += sz[y];
        /*ura aux;
        aux.tip = 0;
        aux.idx = idx, aux.x = x, aux.y = y;
        aux.bipant = bip[x];*/
        /*if (bip[x] == false and bip[y] == false){
            cnt_bad--;}
        if (bip[y] == false)
            bip[x] = false;*/
        //op.push_back(aux);
    }
    else
    {
        /*ura aux;
        aux.tip = 1;
        aux.idx = idx;
        aux.x = x;
        aux.y = y;
        aux.bipant = bip[x];*/
        if (p1.second % 2 == p2.second % 2 and bip[p1.first] == true)
        {
            //cout << "cmon" << p1.first << endl;
            //bip[x] = false;
            cnt_bad++;
        }
        //op.push_back(aux);
    }
}

void und(ura uf)
{
    //cout << "und" << uf.idx << endl;
    if (uf.tip == 0)
    {
        if (bip[uf.y] == false and uf.bipant == false)
            cnt_bad++;
        bip[uf.x] = uf.bipant;
        sz[uf.x] -= sz[uf.y];
        t[uf.y] = {uf.y, 0};
    }
    else
    {
        if (bip[uf.x] != uf.bipant)
            cnt_bad--;
        bip[uf.x] = uf.bipant;
    }
}

bool cmp(ura A, ura B)
{
    if ((A.idx < curi and B.idx >= curi) or (A.idx >= curi and B.idx < curi))
        return A.idx < B.idx;
    else if (A.idx < curi)
        return A.idx < B.idx;
    else
        return A.idx > B.idx;
}

void undo(int idx)
{
    //cout << "u" << idx << endl;
    vector<ura> cur;
    int cate = 0;
    while (true)
    {
        cur.push_back(op.back());
        op.pop_back();
        cate++;
        if (cur.back().idx == idx)
            break;
    }
    while (cate != 0 and !op.empty())
    {
        cur.push_back(op.back());
        op.pop_back();
        cate--;
    }
    for (auto it : cur)
        und(it);
    sort(cur.begin(), cur.end(), cmp);
    for (auto it : cur)
        if (it.idx != idx)
            join(it.idx, u[it.idx], v[it.idx]);
}

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;
        bip[i] = true;
    }
    /*for (int i = 1; i <= m; i++)
        join(i, u[i], v[i]);
    //cout << cnt_bad << endl;
    if (cnt_bad == 0)
    {
        for (int i = 1; i <= q; i++)
        {
            int x, y;
            cin >> x >> y;
            cout << "NO\n";
        }
        return 0;
    }
    int r = 0;
    for (int i = 1; i <= m; i++)
    {
        curi = i;
        while (r < m and cnt_bad > 0)
        {
            r++;
            undo(r);
        }
        if (cnt_bad != 0)
        {
            rmin[i] = m + 1;
            continue;
        }
        rmin[i] = r;
        join(i, u[i], v[i]);
    }
    //for (int i = 1; i <= m; i++)
      //  cout << rmin[i] << ' ';
    //cout << endl;
    for (int i = 1; i <= q; i++)
    {
        int x, y;
        cin >> x >> y;
        if (rmin[x] > y)
            cout << "YES\n";
        else
            cout << "NO\n";
    }*/
    rmin[1] = 1;
    for (int i = m; i >= 1; i--)
    {
        join(i, u[i], v[i]);
        if (cnt_bad != 0)
        {
            rmin[1] = i;
            break;
        }
    }
    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;
}

/**
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
**/

Compilation message

Joker.cpp: In function 'std::pair<int, int> par(int)':
Joker.cpp:26:9: warning: unused variable 'ugabuga' [-Wunused-variable]
   26 |     int ugabuga = 0;
      |         ^~~~~~~

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	44 ms	6088 KB	Output is correct
4	Correct	47 ms	7264 KB	Output is correct
5	Correct	47 ms	7504 KB	Output is correct
6	Correct	45 ms	6196 KB	Output is correct
7	Correct	43 ms	6064 KB	Output is correct
8	Correct	46 ms	5972 KB	Output is correct
9	Correct	48 ms	7360 KB	Output is correct
10	Correct	42 ms	8788 KB	Output is correct
11	Correct	43 ms	7764 KB	Output is correct
12	Correct	45 ms	8788 KB	Output is correct
13	Correct	48 ms	6740 KB	Output is correct
14	Correct	46 ms	7252 KB	Output is correct
15	Correct	44 ms	8232 KB	Output is correct
16	Correct	45 ms	9044 KB	Output is correct