Submission #1093648

#	Time	Username	Problem	Language	Result	Execution time	Memory
1093648		ntdaccode	Joker (BOI20_joker)	C++17	49 / 100	2074 ms	31056 KiB

Joker

#include<bits/stdc++.h>
#define fori(i,a,b) for(int i=a;i<=b;i++)
#define int long long
#define ii pair<int,int>
#define fi first
#define se second
#define pb push_back
using namespace std;
const int mod=1e9+7;
const int M=2e5+10;
const int N=1e3+10;
const int SIZE=316;
int n,m,q;
int x[M],y[M];
struct query
{
  int l,r,idx;
}Q[M];
int ret[M];
// dsu
int id[M];
int dd[M],lz[M];
#define tp tuple<int,int,int,int>
stack<tp> sk;
stack<tp> ks;
int finded(int u,int &v)
{
  v^=lz[u];
  return id[u] < 0 ? u : finded(id[u],v);
}
bool unioned(int tt ,int u,int v)
{
  int pos=0,pos2=0;
  u=finded(u,pos);
  v=finded(v,pos2);

  if(u==v)
  {
    if(pos==pos2) return true;
    return false;
  }
  if(id[u]>id[v]) swap(u,v);
  if(tt!=0)
  {
  sk.push({tt,id[u],id[v],pos==pos2});
  ks.push({tt,u,v,pos==pos2});
  }
  if(pos==pos2) lz[v]^=1;
  id[u]+=id[v];
  id[v]=u;
  return false;
}
int32_t main()
{
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  #define task "1"
  if(fopen(task".inp","r"))
  {
    freopen(task".inp","r",stdin);
    freopen(task".out","w",stdout);
  }
  cin >> n >> m >> q;
  fori(i,1,m) cin >> x[i] >> y[i];
  fori(i,1,q)
  {
    cin >> Q[i].l >> Q[i].r ;
    Q[i].idx=i;
  }
  sort(Q+1,Q+q+1,[&] (const query a,const query b)
       {
         if(a.l/SIZE==b.l/SIZE) return a.r> b.r;
         return  a.l<b.l;
       });
  memset(id,-1,sizeof(id));
  int r=m;
  bool ok=0;
  bool okk=0;
  fori(i,1,q)
  {
   // cout << Q[i].l << " " << Q[i].r << "ds\n";
    if(Q[i-1].l/SIZE!=Q[i].l/SIZE)
    {
      while(!sk.empty())
      {
        auto[tt,idu,idv,dog] = sk.top();
        auto[tt2,u,v,cho] = ks.top();
        sk.pop();
        ks.pop();
        lz[v]^=dog;
        id[u]=idu;
        id[v]=idv;
      }
      okk=0;
      fori(j,max(1ll,(Q[i-1].l/SIZE)*SIZE),min(m,(Q[i].l/SIZE)*SIZE-1)) if(unioned(0,x[j],y[j])) ok=1;
      //fori(i,1,n) cout << lz[i] << " " << id[i] << "\n";
      //cout << Q[i].l << " " << Q[i].r << " " << max(1ll,(Q[i-1].l/SIZE)*SIZE) << " " <<min(m,(Q[i].l/SIZE)*SIZE-1) << "\n";
      r=m;
    }
    //if(Q[i].l==9) cout << sk.size() << " ";
    while(Q[i].r<r&&r/SIZE!=Q[i].l/SIZE)
    {
      if(x[r]==y[r]) continue;
      if(unioned(1,x[r],y[r])) okk=1;
      //if(Q[i].l==7) cout << r << " ";
      r--;
    }
    //if(Q[i].l==2&&Q[i].r==6) cout << r << " ";
    if(ok||okk) ret[Q[i].idx]=1;
    else
    {
      int ook=0;
      //cout << (Q[i].l/SIZE)*SIZE <<  " " << r << "\n";
      fori(j,max(1ll,(Q[i].l/SIZE)*SIZE),Q[i].l-1)
      {
        if(x[j]==y[j]) continue;
        if(unioned(2,x[j],y[j])) ook=1;
      }
      fori(j,Q[i].r+1,r)
      {
        if(x[j]==y[j]) continue;
        if(unioned(2,x[j],y[j])) ook=1;
      }
      while(!sk.empty())
      {
        auto[tt,idu,idv,cho] = sk.top();
        auto[tt2,u,v,dog] = ks.top();
        if(tt!=2) break;
        sk.pop();
        ks.pop();
        lz[v]^=dog;
        id[u]=idu;
        id[v]=idv;
      }

      if(ook) ret[Q[i].idx]=1;
    }

  }
  fori(i,1,q)
  {
    if(ret[i]) cout << "YES\n";
    else cout << "NO\n";
  }
}

Compilation message (stderr)

Joker.cpp: In function 'int32_t main()':
Joker.cpp:61:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   61 |     freopen(task".inp","r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
Joker.cpp:62:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   62 |     freopen(task".out","w",stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

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