oj.uz

Submission #649832

# Submission time Handle Problem Language Result Execution time Memory
649832 2022-10-11T11:42:48 Z welleyth Joker (BOI20_joker) C++17
25 / 100
 494 ms 25988 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, 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 296 ms 25988 KB Output is correct
4 Correct 114 ms 19136 KB Output is correct
5 Correct 203 ms 22212 KB Output is correct
6 Correct 235 ms 20216 KB Output is correct
7 Correct 258 ms 19216 KB Output is correct
8 Correct 231 ms 20672 KB Output is correct
9 Correct 246 ms 20996 KB Output is correct
10 Correct 474 ms 20892 KB Output is correct
11 Correct 237 ms 19004 KB Output is correct
12 Correct 364 ms 20560 KB Output is correct
13 Correct 174 ms 18312 KB Output is correct
14 Correct 237 ms 20424 KB Output is correct
15 Correct 322 ms 20116 KB Output is correct
16 Correct 494 ms 20872 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 -