Submission #925780

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
925780	2024-02-12T08:43:41 Z	vjudge1	Joker (BOI20_joker)	C++17	Compilation error	0 ms	0 KB

Joker

//Bismillahir-Rahmanir-Rahim

#include <bits/stdc++.h>
//#pragma comment(linker, "/stack:200000000")
//#pragma GCC optimize("O1,O2,O3,Ofast,unroll-loops")
//#pragma GCC target("sse,sse2,sse3,sse4,sse4.1,sse4.2,popcnt,avx,avx2")

#define pb push_back
#define pii pair <int, int>
#define pll pair <long long, long long>
#define pld pair <long double, long double>
#define ll long long
#define ld long double
#define x first
#define y second
#define all(v) v.begin(),v.end()
#define sz(s) (int)s.size()
#define skip continue
#define bpop(x) (ll)__builtin_popcountll(x)

using namespace std;

const int N = 2e5 + 7;
const int M = 1e3 + 7;
const int maxA = 2e6 + 7;
const int inf = 1e9 + 7;
const ll INF = 2e18 + 7;
const int MOD = 1e9 + 7;
const ld eps = 1e-9;

pii dir[] = {{0, 1}, {1, 0}, {0, -1}, {-1, 0}};

//mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

//#define int long long

pii E[N];
vector <int> g[N];
int n, m, q, dist[N];
vector <pii> qs;
bool bfs(int st) {
    queue <int> q;
    q.push(st), dist[st] = 0;
    while (!q.empty()) {
        int v = q.front();
        q.pop();
        for (auto to : g[v]) {
            if (dist[to] == -1)dist[to] = 1 - dist[v], q.push(to);
            else if (dist[v] == dist[to]) {
                //cout << v << ':' << dist[v] << ' ' << to << ':' << dist[to] << '\n';
                return 1;
            }
        }
    }
    return 0;
}
void subtask12() {
    for (auto p : qs) {
        int l, r;
        tie(l, r) = p;
        for (int i = 1;i <= n;i++)g[i].clear(), dist[i] = -1;
        for (int i = 1;i <= m;i++) {
            if (l <= i && i <= r)skip;
            g[E[i].x].pb(E[i].y), g[E[i].y].pb(E[i].x);
            //cout << E[i].x << ' ' << E[i].y << '\n';
        }
        bool ans = 0;
        for (int i = 1;i <= n;i++) {
            if (dist[i] == -1)ans |= bfs(i);
        }
        cout << (ans ? "YES" : "NO") << '\n';
    }
    exit(0);
}
int color[N];
vector <int> vs[N];
int get(int x) {
    return (x == color[x] ? x : color[x] = get(color[x]));
}
void subtask3() {
    for (int i = 1;i <= n;i++)dist[i] = -1, color[i] = i, vs[i] = {i};
    int pos = inf;
    for (int i = 1;i <= m;i++) {
        int x = E[i].x, y = E[i].y;
        int Lx = get(x), Ly = get(y);
        if (sz(vs[Lx]) > sz(vs[Ly]))swap(x, y), swap(Lx, Ly);
        if (dist[x] == -1 && dist[y] == -1)dist[x] = 0, dist[y] = 1, color[x] = y, vs[y].pb(x), vs[x].clear();
        else if (dist[x] == -1)dist[x] = 1 - dist[Ly], color[x] = Ly, vs[Ly].pb(x), vs[x].clear();
        else {
            if (Lx != Ly) {
                color[Lx] = Ly;
                for (auto v : vs[Lx])vs[Ly].pb(v), color[v] = Ly, dist[v] ^= (dist[v] == dist[to]);
                vs[Lx].clear();
            }
            else if (dist[x] == dist[y]) {
                pos = i;
                break;
            }
        }
    }
    for (auto p : qs) {
        int r = p.y;
        if (r >= pos)cout << "YES\n";
        else cout << "NO\n";
    }
    exit(0);
}
void solve() {
    cin >> n >> m >> q;
    for (int i = 1;i <= m;i++) {
        int x, y;
        cin >> x >> y;
        E[i] = {x, y};
    }
    bool solve_for_pref = 1;
    for (int i = 0;i < q;i++) {
        int l, r;
        cin >> l >> r;
        qs.pb({l, r});
        solve_for_pref &= (l == 1);
    }
    if (n <= 2000 && m <= 2000 && q <= 2000)subtask12();
    if (solve_for_pref)subtask3();
}
signed main() {
    //srand(time(NULL));
    ios_base::sync_with_stdio(0);
    cout.tie(0);
    //freopen("tests.in", "r", stdin);
    //freopen("milkorder.out", "w", stdout);
    int test = 1;
    //cin >> test;
    for (int t = 1;t <= test;t++) {
        //cout << "Case " << t << ": ";
        solve();
    }
    return 0;
}

Compilation message

Joker.cpp: In function 'void subtask3()':
Joker.cpp:92:95: error: 'to' was not declared in this scope; did you mean 'tm'?
   92 |                 for (auto v : vs[Lx])vs[Ly].pb(v), color[v] = Ly, dist[v] ^= (dist[v] == dist[to]);
      |                                                                                               ^~
      |                                                                                               tm