oj.uz

Submission #750729

# Submission time Handle Problem Language Result Execution time Memory
750729 2023-05-30T08:22:12 Z GrindMachine Joker (BOI20_joker) C++17
0 / 100
 2000 ms 17492 KB 
// Om Namah Shivaya

#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;

template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x, y) ((x + y - 1) / (y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "YES" << endl
#define no cout << "NO" << endl

#define rep(i, n) for(int i = 0; i < n; ++i)
#define rep1(i, n) for(int i = 1; i <= n; ++i)
#define rev(i, s, e) for(int i = s; i >= e; --i)
#define trav(i, a) for(auto &i : a)

template<typename T>
void amin(T &a, T b) {
    a = min(a, b);
}

template<typename T>
void amax(T &a, T b) {
    a = max(a, b);
}

#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif

/*

refs:
edi
some submissions

*/

const int MOD = 1e9 + 7;
const int N = 2e5 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;

struct DSU {
    vector<int> par, rankk;
    vector<int> weight;
    bool is_bip;
    vector<array<int,5>> history;

    DSU() {

    }

    DSU(int n) {
        init(n);
    }

    void init(int n) {
        par = vector<int>(n + 1);
        rankk = vector<int>(n + 1);
        weight = vector<int>(n + 1);
        is_bip = true;
        rep(i, n + 1) create(i);
    }

    void create(int u) {
        par[u] = u;
        rankk[u] = 0;
        weight[u] = 0;
    }

    pii find(int u) {
        if (u == par[u]) return {u,0};
        auto [p, cp] = find(par[u]);
        return {p, cp ^ weight[u]};        
    }

    bool same(int u, int v) {
        return find(u).ff == find(v).ff;
    }

    void merge(int u, int v) {
        auto [pu,cu] = find(u);
        auto [pv,cv] = find(v);

        history.pb({pu, par[pu], rankk[pu], weight[pu], is_bip});
        history.pb({pv, par[pv], rankk[pv], weight[pv], is_bip});

        if(pu == pv){
            if(cu == cv){
                is_bip = false;
            }

            return;
        }

        int w = cu ^ cv ^ 1;
        u = pu, v = pv;

        if (rankk[u] == rankk[v]) rankk[u]++;
        if (rankk[u] < rankk[v]) swap(u, v);

        par[v] = u;
        weight[v] = w;
    }

    void rollback(int times){
        times *= 2;
        rep(t,times){
            auto [u,pu,rnk,w,bip] = history.back();
            history.pop_back();

            par[u] = pu;
            rankk[u] = rnk;
            weight[u] = w;
            is_bip = bip;
        }
    }
};

vector<pii> edges(N);
DSU dsu(N);
vector<int> best(N);

void go(int l1, int r1, int l2, int r2){
    if(l1 > r1) return;

    int mid = (l1 + r1) >> 1;
    int opt_mid = r2;
    int cnt = 0;

    for(int i = l1; i < opt_mid; ++i){
        auto [u,v] = edges[i];
        dsu.merge(u,v);
        cnt++;
    }

    rev(i,r2,l2){
        auto [u,v] = edges[i];
        dsu.merge(u,v);
        cnt++;

        if(dsu.is_bip){
            opt_mid = i - 1;
        }
        else{
            break;
        }
    }

    best[mid] = opt_mid;
    dsu.rollback(cnt);

    // add everybody > opt_mid
    cnt = 0;
    for(int i = opt_mid + 1; i <= r2; ++i){
        auto [u,v] = edges[i];
        dsu.merge(u,v);
        cnt++;
    }

    go(l1,mid-1,l2,opt_mid);
    dsu.rollback(cnt);

    // add everybody < mid+1
    cnt = 0;
    for(int i = l1; i <= mid; ++i){
        auto [u,v] = edges[i];
        dsu.merge(u,v);
        cnt++;
    }

    go(mid+1,r1,opt_mid,r2);
    dsu.rollback(cnt);
}

void solve(int test_case)
{
    int n,m,q; cin >> n >> m >> q;
    rep1(i,m) cin >> edges[i].ff >> edges[i].ss;

    go(1,m,1,m);

    assert(dsu.history.empty());

    // rep1(l,n){
    //     cout << best[l] << " ";
    // }
    // cout << endl;

    while(q--){
        int l,r; cin >> l >> r;
        if(r < best[l]){
            yes;
        }
        else{
            no;
        }
    }
}

int main()
{
    fastio;

    int t = 1;
    // cin >> t;

    rep1(i, t) {
        solve(i);
    }

    return 0;
}

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 5036 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 5036 KB Output is correct
4 Incorrect 3 ms 4948 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #3
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 Execution timed out 2037 ms 17492 KB Time limit exceeded
4 Halted 0 ms 0 KB -

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 5036 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 5036 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 5036 KB Output is correct
4 Incorrect 3 ms 4948 KB Output isn't correct
5 Halted 0 ms 0 KB -