Submission #765269

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
765269	2023-06-24T10:05:05 Z	canadavid1	Joker (BOI20_joker)	C++14	25 / 100	205 ms	10132 KB

Joker

#include <bits/stdc++.h>


using namespace std;

vector<bool> diff;
vector<int> p;
vector<int> siz;

pair<int,bool> find(int a,bool len=0)
{
    if (p[a] == -1) return {a,len};
    return find(p[a],len^diff[a]); // no path compression
}

bool unite(int a,int b) // true if works, false elsewise
{
    auto av = find(a);
    auto bv = find(b);
    if (av.first == bv.first) return av.second!=bv.second;
    
    if (siz[av.first] > siz[bv.first]) swap(av,bv);
    // b > a
    p[av.first] = bv.first;
    siz[bv.first] += siz[av.first];
    if (av.second == bv.second) diff[av.first] = true;
    return true;
}


vector<pair<int,int>> edge;
vector<pair<int,int>> query;
vector<bool> queryvalid;
int N,M,Q,added;
int main()
{
    cin >> N >> M >> Q;
    diff.assign(N+1,false);
    p.assign(N+1,-1);
    siz.assign(N+1,1);
    queryvalid.assign(Q,false);
    edge.push_back({0,0});
    for(int i = 0; i < M; i++)
    {
        int l,r;
        cin >> l >> r;
        edge.push_back({l,r});     
    }
    for(int i = 0; i < Q; i++)
    {
        int l,r;
        cin >> l >> r;
        query.push_back({r,i});
    }
    sort(query.begin(),query.end());
    added = M;
    bool valid = true;
    while(query.size())
    {
        for(;added>query.back().first;added--)
        {
            valid &= unite(edge[added].first,edge[added].second);
        }
        queryvalid[query.back().second] = valid;
        query.pop_back();
    }
    for (auto &&i : queryvalid)
    {
        cout << (i ? "NO\n" : "YES\n");
    }

/*
    vector<vector<int>> neigh(N+1);
    vector<pair<int,int>> edge;
    for(int i = 0; i < N; i++)
    {
        int u,v;
        cin >> u >> v;
        neigh[u].push_back(v);
        neigh[v].push_back(u);
        edge.push_back({u,v});
    }
    vector<pair<int,int>> query(Q);
    int l;
    for (auto &&r : query) cin >> l >> r.first;
    for(int i = 0; i < Q; i++) query[i].second = i;
    sort(query.begin(),query.end());
    vector<bool> result;
    int s;
    while(query.size())
    {

    }*/
}

Subtask #1
0 / 6.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	0 ms	212 KB	Output is correct
2	Correct	1 ms	212 KB	Output is correct
3	Incorrect	0 ms	212 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	212 KB	Output is correct
2	Correct	1 ms	212 KB	Output is correct
3	Incorrect	0 ms	212 KB	Output isn't correct
4	Halted	0 ms	0 KB	-

Subtask #3
25.0 / 25.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	0 ms	212 KB	Output is correct
2	Correct	1 ms	212 KB	Output is correct
3	Correct	178 ms	5748 KB	Output is correct
4	Correct	172 ms	6804 KB	Output is correct
5	Correct	189 ms	6608 KB	Output is correct
6	Correct	185 ms	9240 KB	Output is correct
7	Correct	188 ms	9272 KB	Output is correct
8	Correct	163 ms	8544 KB	Output is correct
9	Correct	191 ms	8844 KB	Output is correct
10	Correct	182 ms	9932 KB	Output is correct
11	Correct	185 ms	9356 KB	Output is correct
12	Correct	204 ms	9996 KB	Output is correct
13	Correct	200 ms	8560 KB	Output is correct
14	Correct	182 ms	8996 KB	Output is correct
15	Correct	182 ms	9652 KB	Output is correct
16	Correct	205 ms	10132 KB	Output is correct