Submission #1054269

#	Time	Username	Problem	Language	Result	Execution time	Memory
1054269		Mighilon	Joker (BOI20_joker)	C++17	39 / 100	231 ms	21832 KiB

Joker

#include <bits/stdc++.h>
using namespace std;
 
#ifdef DEBUG
#include "../Library/debug.h"
#else
#define dbg(x...)
// #define cin fin
// #define cout fout
// const string FILE_NAME = ""; ifstream fin(FILE_NAME + ".in"); ofstream fout(FILE_NAME + ".out");
#endif
 
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pi;
typedef pair<ll, ll> pl;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<pi> vpi;
typedef vector<pl> vpl; 
 
#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define F0R(i, a) for (int i = 0; i < (a); ++i)
#define FORd(i, a, b) for (int i = (b) - 1; i >= (a); --i)
#define F0Rd(i, a) for (int i = (a) - 1; i >= 0; --i)
#define trav(a, x) for (auto& a : x)
#define f first 
#define s second
#define pb push_back
#define sz(x) (int)(x).size()
#define all(x) x.begin(), x.end()
 
const char nl = '\n';
const int INF = 1e9;
const int MOD = 1e9 + 7;

vector<vi> adj;
vi edges, good;
vi color;
bool cycle = false;

void dfs(int u, int p, int c){
    if(color[u] != -1 && color[u] != c){
        cycle = true;
        return;
    }
    if(color[u] != -1)
        return;
    color[u] = c;
    trav(id, adj[u]){
        if(!good[id]) continue;
        int v = edges[id] ^ u;
        if(v == p)
            continue;
        dfs(v, u, c ^ 1);
    }
}

void solve(){
    int n, m, q;
    cin >> n >> m >> q;
    adj.resize(n);
    edges.resize(m);
    F0R(i, m){
        int a, b;
        cin >> a >> b;
        --a, --b;
        edges[i] = a ^ b;
        adj[a].pb(i);
        adj[b].pb(i);
    }
    if(max({n, m, q}) <= 2000){
        color.resize(n);
        good.resize(m);
        while(q--){
            int a, b;
            cin >> a >> b;
            a--, b--;
            color = vector<int>(n, -1);
            F0R(i, m){
                if(i >= a && i <= b)
                    good[i] = false;
                else good[i] = true;
            }
            cycle = false;
            F0R(i, n){
                if(color[i] == -1)
                    dfs(i, -1, 1);
            }
            if(cycle)
                cout << "YES\n";
            else cout << "NO\n";
            dbg(color)
        }
        return;
    }
    color.resize(n);
    good.resize(m);
    auto f = [&](int a, int b){
        color = vector<int>(n, -1);
        F0R(i, m){
            if(i >= a && i <= b)
                good[i] = false;
            else good[i] = true;
        }
        cycle = false;
        F0R(i, n){
            if(color[i] == -1)
                dfs(i, -1, 1);
        }
        return cycle;
    };
    vector<array<int, 3>> queries(q);
    F0R(i, q){
        cin >> queries[i][0] >> queries[i][1];
        queries[i][0]--, queries[i][1]--;
        queries[i][2] = i;
    }
    sort(all(queries), [&](array<int, 3>& a, array<int, 3>& b) {return a[1] < b[1];});
    int l = 0, r = q - 1, point = -1;
    while(l <= r){
        int m = (l + r) / 2;
        if(f(queries[m][0], queries[m][1])){
            point = m;
            l = m + 1;
        }
        else{
            r = m - 1;
        }
    }
    if(point == -1){
        F0R(i, q){
            cout << "NO\n";
        }
    }
    else{
        F0R(i, point + 1)
            queries[i][0] = 1;
        FOR(i, point + 1, q)
            queries[i][0] = 0;
        sort(all(queries), [&](array<int, 3>& a, array<int, 3>& b){return a[2] < b[2];});
        F0R(i, q){
            if(queries[i][0] == 1)
                cout << "YES\n";
            else cout << "NO\n";
        }
    }
}
 
int32_t main(){
    ios::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
    
    int TC = 1;
    // cin >> TC;
    while(TC--){
        solve();
    }
    return 0;
}

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