Submission #648597

#	Time	Username	Problem	Language	Result	Execution time	Memory
648597		mychecksedad	Joker (BOI20_joker)	C++17	39 / 100	424 ms	38536 KiB

Joker

/* Author : Mychecksdead */
#include<bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using namespace std;
typedef long long int ll;
typedef long double ld;
#define MOD (1000000000+7)
#define MOD1 (998244353)
#define PI 3.1415926535
#define pb push_back
#define setp() cout << setprecision(15)
#define all(x) x.begin(), x.end()
#define oset tree<int, null_type,less_equal<int>, rb_tree_tag,tree_order_statistics_node_update>
#define debug(x) cerr << #x << " is " << x << '\n';
const int N = 1e6+100, M = 2e5+10, F = 2147483646, K = 20;


int n, m, q, l, r;
bool ok;
vector<pair<int, int>> g[N];
bitset<M> vis, pos;
void dfs(int v, int p, bool c){
    vis[v] = 1;
    pos[v] = c;
    for(auto k: g[v]){
        int u = k.first;
        if(l <= k.second && k.second <= r) continue;
        if(u != p){
            if(vis[u])
                ok |= pos[v] == pos[u];
            else
                dfs(u, v, !c);
        }
    }
}
void solve(){
    cin >> n >> m >> q;
    for(int i = 0; i < m; ++i){
        int u, v; cin >> u >> v;
        g[u].pb({v, i + 1});
        g[v].pb({u, i + 1});
    }
    if(n <= 2000){
        for(int i = 0; i < q; ++i){
            cin >> l >> r;
            vis = 0;
            ok = 0;
            for(int v = 1; v <= n; ++v) if(!ok && !vis[v]) dfs(v, v, 0);
            if(ok) cout << "YES\n";
            else cout << "NO\n";
        }
    }
    else{
        int lb = 1, rb = m, lim = 0;
        while(lb <= rb){
            int mid = (lb + rb) >> 1;
            l = 1, r = mid;
            vis = 0;
            ok = 0;
            for(int v = 1; v <= n; ++v) if(!ok && !vis[v]) dfs(v, v, 0);
            if(ok){
                lim = mid;
                lb = mid + 1;
            }else{
                rb = mid - 1;
            }
        }
        for(int i = 1; i <= q; ++i){
            cin >> l >> r;
            cout << (r <= lim ? "YES": "NO") << '\n';
        }
       }
}





int main(){
    cin.tie(0); ios::sync_with_stdio(0);
    int T = 1, aa;
    // cin >> T;aa=T;
    while(T--){
        // cout << "Case #" << aa-T << ": ";
        solve();
        cout << '\n';
    }
    return 0;
 
}

Compilation message (stderr)

Joker.cpp: In function 'int main()':
Joker.cpp:82:16: warning: unused variable 'aa' [-Wunused-variable]
   82 |     int T = 1, aa;
      |                ^~

• Subtask 1: 6 / 6
• Subtask 2: 8 / 8
• Subtask 3: 25 / 25
• Subtask 4: 0 / 10
• Subtask 5: 0 / 22
• Subtask 6: 0 / 29