oj.uz

Submission #649829

# Submission time Handle Problem Language Result Execution time Memory
649829 2022-10-11T11:39:51 Z welleyth Joker (BOI20_joker) C++17
0 / 100
 287 ms 26072 KB 
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;

//#define int long long
#define pb push_back
#define mp make_pair

#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")

constexpr int N = (int)2e5 + 111;
constexpr int md = (int)2e5 + 111;

mt19937 rnd(time(nullptr));

vector<int> g[N];
bool used[2][N];
bool c[2][N];

bool dfs(int v,int r,int pr = -1){
    used[r][v] = true;
    c[r][v] = true;
    for(auto& to : g[v]){
        if(pr == to)
            continue;
        if(used[r^1][to]){
            if(c[r][v]&c[r][to])
                return true;
            continue;
        }
        c[r^1][to] = true;
        if(dfs(to,r^1,v))
            return true;
    }
    return false;
}

int n,m,q;
vector<pair<int,int>> edges;

bool can(int l,int r){
    for(int j = 0; j <= n; j++){
        used[0][j] = false;
        used[1][j] = false;
        c[0][j] = c[1][j] = 0;
        g[j].clear();
    }
    bool have = false;
    for(int j = 0; j < l-1; j++){
        auto&[a,b] = edges[j];
        g[a].pb(b);
        g[b].pb(a);
    }
    for(int j = r; j < m; j++){
        auto&[a,b] = edges[j];
        g[a].pb(b);
        g[b].pb(a);
    }
    for(int j = 1; j <= n; j++){
        if(!used[0][j] && !used[1][j]){
            c[0][j] = 1;
            if(dfs(j,0)){
                return true;
            }
        }
    }
    return false;
}

void solve(){
    cin >> n >> m >> q;

    for(int i = 0; i < m; i++){
        int a,b;
        cin >> a >> b;
        edges.pb(mp(a,b));
    }

    bool answer[q];
    bool f = true;
    if(!can(1,0))
        f = false;

    vector<pair<int,int>> Queries[m+1];

    for(int i = 0; i < q; i++){
        int l,r;
        cin >> l >> r;
        if(!f){
            cout << "NO\n";
            return;
        }
        Queries[l].pb(mp(r,i));
    }
    if(!f)
        return;
    for(int i = 0; i <= m; i++){
        if(Queries[i].empty())
            continue;
        sort(Queries[i].rbegin(),Queries[i].rend());
        if(!can(i,i)){
            for(auto&[r,id] : Queries[i]){
                answer[id] = 0;
            }
            continue;
        }
        int L = i, R = m;
        while(R - L > 1){
            int mid = (L+R)>>1;
            if(can(i,mid))
                L = mid;
            else
                R = mid;
        }
        for(auto&[r,id] : Queries[i]){
            if(r <= L)
                answer[id] = 1;
            else
                answer[id] = 0;
        }
    }

    for(int i = 0; i < q; i++){
        cout << (answer[i] ? "YES" : "NO") << "\n";
    }

    return;
}

signed main(){
    ios::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr);
//    init();
    int tests = 1;
//    cin >> tests;
    for(int test = 1; test <= tests; test++){
//        cerr << "test = " << test << "\n";
        solve();
    }
    return 0;
}
/**
6 8 2
1 3
1 5
1 6
2 5
2 6
3 4
3 5
5 6
4 7
4 8

**/

Compilation message

Joker.cpp: In function 'bool can(int, int)':
Joker.cpp:52:10: warning: unused variable 'have' [-Wunused-variable]
   52 |     bool have = false;
      |          ^~~~

Subtask #1
0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4948 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Correct 3 ms 4948 KB Output is correct
4 Incorrect 3 ms 4948 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #2
0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4948 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Correct 3 ms 4948 KB Output is correct
4 Incorrect 3 ms 4948 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #3
0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4948 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Correct 287 ms 26072 KB Output is correct
4 Incorrect 98 ms 18496 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #4
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4948 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Correct 3 ms 4948 KB Output is correct
4 Incorrect 3 ms 4948 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #5
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4948 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Correct 3 ms 4948 KB Output is correct
4 Incorrect 3 ms 4948 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #6
0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4948 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Correct 3 ms 4948 KB Output is correct
4 Incorrect 3 ms 4948 KB Output isn't correct
5 Halted 0 ms 0 KB -