oj.uz

Submission #649833

# Submission time Handle Problem Language Result Execution time Memory
649833 2022-10-11T11:43:49 Z welleyth Joker (BOI20_joker) C++17
25 / 100
 470 ms 23976 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";
            continue;
        }
        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-1, R = m;
        while(R - L > 1){
            int mid = (L+R)>>1;
            if(can(i,mid))
                L = mid;
            else
                R = mid;
        }
        f = can(i,L);
        for(auto&[r,id] : Queries[i]){
            if(r <= L && f)
                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
25.0 / 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 272 ms 23976 KB Output is correct
4 Correct 131 ms 19152 KB Output is correct
5 Correct 204 ms 22388 KB Output is correct
6 Correct 276 ms 20096 KB Output is correct
7 Correct 316 ms 19112 KB Output is correct
8 Correct 211 ms 20680 KB Output is correct
9 Correct 290 ms 20940 KB Output is correct
10 Correct 457 ms 20892 KB Output is correct
11 Correct 233 ms 19008 KB Output is correct
12 Correct 353 ms 20660 KB Output is correct
13 Correct 183 ms 18368 KB Output is correct
14 Correct 222 ms 20420 KB Output is correct
15 Correct 350 ms 20160 KB Output is correct
16 Correct 470 ms 20984 KB Output is correct

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 -