Submission #782559

#	Time	Username	Problem	Language	Result	Execution time	Memory
782559		Cookie	Joker (BOI20_joker)	C++14	0 / 100	325 ms	23936 KiB

Joker

#include<bits/stdc++.h>
#include<fstream>
using namespace std;
ifstream fin("VNOICUP.INP");
ofstream fout("VNOICUP.OUT");
#define sz(a) (int)a.size()
#define ll long long
#define pb push_back
#define forr(i, a, b) for(int i = a; i < b; i++)
#define dorr(i, a, b) for(int i = a; i >= b; i--)
#define ld long double
#define vt vector
#include<fstream>
#define fi first
#define se second
#define pll pair<ll, ll>
#define pii pair<int, int>
const ld PI = 3.14159265359;
using u128 = __uint128_t;
//const int x[4] = {1, -1, 0, 0};
//const int y[4] = {0, 0, 1, -1};
const ll mod = 1000001;
const int mxn = 3e5 + 1, mxq = 2e5 + 5, sq = 400, mxv = 2e7 + 5, p = 31;
//const int base = (1 << 18);
const ll inf = 1e9 + 5, neg = -69420;
struct DSU{
    vt<pii>past_p, past_sz;
    vt<int>checkpoint;
    int p[2 * mxn + 1], sz[2 * mxn + 1];
    void init(){
        for(int i = 0; i <= 2 * mxn; i++){
            p[i] = i; sz[i]  = 1;
        }
        past_sz.clear(); past_p.clear(); checkpoint.clear();
    }
    int fp(int a){
        if(p[a] == a)return(a);
        return(fp(p[a]));
    }
    bool check(int u, int v){
        return(fp(u) == fp(v));
    }
    void unon(int a, int b){

        a = fp(a); b = fp(b);
        if(sz[a] < sz[b])swap(a, b);
        past_sz.pb({a, sz[a]}); past_p.pb({b, p[b]});
        if(a != b){
            sz[a] += sz[b]; p[b] = a;
        }
    }
    void rollback(){
        //int before = p[past_p.back().fi], after = past_p.back().se;
        //if(before != past_p.back().fi && after == past_p.back().fi)cnt++;
        p[past_p.back().fi] = past_p.back().se; past_p.pop_back();
        sz[past_sz.back().fi] = past_sz.back().se; past_sz.pop_back();
    }
    void save(){
        checkpoint.pb(past_sz.size());
    }
    void to_last(int s){
        while(past_sz.size() != s)rollback();
        
    }
};
DSU dsu;
int n, m, q;
vt<pii>edge;
int to[mxn + 1];
void input(){
    cin >> n >> m >> q;
    edge.pb({0, 1});
    for(int i = 0; i < m; i++){
        int u, v; cin >> u >> v;
       edge.pb({u, v});
    }

}
void solve(int l, int r, int candl, int candr){
    if(l > r)return;
    if(candl == candr){
        for(int i = l; i <= r; i++)to[i] = candl;
        return;
    }
    dsu.save();
    int check1 = dsu.past_sz.size();
    bool ok = 1;
    int mid = (l + r) >> 1;
    for(int i = l; i <= mid; i++){
        auto [u, v] = edge[i];
        dsu.unon(u << 1, v << 1 | 1); dsu.unon(v << 1, u << 1 | 1);
        if(dsu.check(u << 1, u << 1 | 1) || dsu.check(v << 1, v << 1 | 1)){
            ok = 0; break;
        }
    }
    int check2 = dsu.past_sz.size();
    dsu.save();
    int res = candr;
    while(res && ok){
        res--;
        if(res == 0)break;
        auto [u, v] = edge[res];
        dsu.unon(u << 1, v << 1 | 1); dsu.unon(v << 1, u << 1 | 1);
        if(dsu.check(u << 1, u << 1 | 1) || dsu.check(v << 1, v << 1 | 1)){
            ok = 0; break;
        }

    }
    to[l] = res;
    dsu.to_last(check2);
    solve(mid + 1, r, res, candr);
    dsu.to_last(check1);
    for(int i = max(1, res); i < candr; i++){
        auto [u, v] = edge[i];
        dsu.unon(u << 1, v << 1 | 1); dsu.unon(v << 1, u << 1 | 1);
    }
    solve(l, mid - 1, candl, res);
    dsu.to_last(check1);
}
void process(){
   dsu.init();
   solve(0, m, 0, m + 1);
   while(q--){
    int l, r; cin >> l >> r;
    cout << ((to[l - 1] > r) ? "YES" : "NO") << "\n";
   }
}

signed main(){
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    input();
    process();
    return(0);
}

Compilation message (stderr)

Joker.cpp: In member function 'void DSU::to_last(int)':
Joker.cpp:62:30: warning: comparison of integer expressions of different signedness: 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   62 |         while(past_sz.size() != s)rollback();
      |               ~~~~~~~~~~~~~~~^~~~
Joker.cpp: In function 'void solve(int, int, int, int)':
Joker.cpp:90:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   90 |         auto [u, v] = edge[i];
      |              ^
Joker.cpp:102:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  102 |         auto [u, v] = edge[res];
      |              ^
Joker.cpp:114:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  114 |         auto [u, v] = edge[i];
      |              ^

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