oj.uz

Submission #776340

# Submission time Handle Problem Language Result Execution time Memory
776340 2023-07-07T17:14:28 Z I_Love_EliskaM_ Highway Tolls (IOI18_highway) C++14
69 / 100
 179 ms 17792 KB 
#include "highway.h"
#include <bits/stdc++.h>
using namespace std;
#define forn(i,n) for(int i=0;i<n;++i)
#define ll long long
#define pb push_back
#define all(x) x.begin(), x.end()
const ll inf = 1e18;
#define pi pair<int,int>
#define f first
#define s second

const int maxn=2e5;
vector<pi> adj[maxn];
pi e[maxn];
vector<int> z;
void dfs(int u, int p) {
  for(auto&ed:adj[u]) {
    int v=ed.f, i=ed.s;
    if (v==p) continue;
    e[i]={u,v};
    z.pb(i);
    dfs(v,u);
  }
}


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

void find(int n, vector<int>u, vector<int>v, int a, int b) {
  int shift=0;
  int Z=(a&1)&(b&1);
  int Q=Z;
  while (!((a^b)&1)) {
  	++shift;
  	a>>=1;
  	b>>=1;
  }
  int m=u.size();
  vector<int> f,s;
  ll x;
  Z^=a&1; Z^=1;
  forn(it,18) {
    f.clear(), s.clear();
    vector<int> ok(n);
    forn(i,n) ok[i]=rng()&1;
    forn(i,n) (ok[i]?f:s).pb(i);
    if (min(f.size(),s.size())==0) {
      --it; continue;
    }
    vector<int> q(m);
    forn(i,m) q[i]=(ok[u[i]]==ok[v[i]])^Z;
    x = ask(q);
    x>>=shift;
    x^=Q;
    if (x&1) {
    	//cout<<"!!! : "<<a<<' '<<b<<'\n';
    	//cout<<ask(q)<<'\n';
    	//for(auto&x:f) cout<<x<<' '; cout<<'\n';
    	//for(auto&y:s) cout<<y<<' '; cout<<'\n';
      break;
    }
  }
  if (!(x&1)) exit(0);
  if (f.size()>s.size());
  assert(f.size());
  int l=0, r=f.size()-1;
  while (l<r) {
    int mid=(l+r)>>1;
    vector<int> ok(n);
    for(auto&x:s) ok[x]=1;
    forn(i,mid+1) ok[f[i]]=1;
    vector<int> q(m,0);
    forn(i,m) q[i]=(ok[u[i]]==ok[v[i]])^Z;
    x = ask(q);
    x>>=shift;
    x^=Q;
    if (x&1) l=mid+1;
    else r=mid;
  }
  int st = f[r];
  //cout<<"! "<<st<<'\n';
  vector<vector<pi>> g(n);
  forn(i,m) {
    g[u[i]].pb({v[i],i});
    g[v[i]].pb({u[i],i});
  }
  vector<int> vis(n); vis[st]=1;
  queue<int> q; q.push(st);
  while (q.size()) {
    auto u=q.front();q.pop();
    for(auto&ed:g[u]) {
      int v=ed.f, i=ed.s;
      if (vis[v]) continue;
      vis[v]=1;
      e[i]={u,v};
      q.push(v);
      z.pb(i);
    }
  }
  l=0, r=n-2;
  ll S=ask(vector<int>(m,1));
  while (l<r) {
    int mid=(l+r)>>1;
    vector<int> q(m,1);
    for(int i=mid+1;i<z.size();++i) q[z[i]]=0;
    ll x=ask(q);
    if (x==S) r=mid;
    else l=mid+1;
  }
  answer(st,e[z[r]].s);

}

void find_pair(int n, vector<int>u, vector<int>v, int a, int b) {
  int m=u.size();
  if (m!=n-1) {
    find(n,u,v,a,b);
    return;
  }
  forn(i,n-1) adj[u[i]].pb({v[i],i}), adj[v[i]].pb({u[i],i});
  int k=0; forn(i,n) if (adj[i].size()==1) k=i;
  dfs(k,-1);

  ll s = ask(vector<int>(m,1));

  int l=0, r=n-2;
  while (l<r) {
    int m=(l+r)>>1;
    vector<int> q(n-1);
    forn(i,m+1) q[z[i]]=1;
    ll x=ask(q);
    if (x==s) r=m;
    else l=m+1;
  }

  k = e[z[r]].s;
  //k=0;
  z.clear();
  dfs(k,-1);

  l=0, r=n-2;
  while (l<r) {
    int m=(l+r)>>1;
    vector<int> q(n-1);
    forn(i,m+1) q[z[i]]=1;
    ll x=ask(q);
    if (x==s) r=m;
    else l=m+1;
  }
  answer(k,e[z[r]].s);

}

Compilation message

highway.cpp: In function 'void find(int, std::vector<int>, std::vector<int>, int, int)':
highway.cpp:106:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  106 |     for(int i=mid+1;i<z.size();++i) q[z[i]]=0;
      |                     ~^~~~~~~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4944 KB Output is correct
2 Correct 3 ms 4944 KB Output is correct
3 Correct 3 ms 4944 KB Output is correct
4 Correct 2 ms 4944 KB Output is correct
5 Correct 2 ms 4944 KB Output is correct
6 Correct 2 ms 4944 KB Output is correct
7 Correct 2 ms 4944 KB Output is correct
8 Correct 2 ms 4944 KB Output is correct
9 Correct 2 ms 4944 KB Output is correct
10 Correct 3 ms 4944 KB Output is correct
11 Correct 2 ms 4944 KB Output is correct
12 Correct 2 ms 4944 KB Output is correct

Subtask #2
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 5072 KB Output is correct
2 Correct 9 ms 5720 KB Output is correct
3 Correct 123 ms 11324 KB Output is correct
4 Correct 97 ms 11344 KB Output is correct
5 Correct 80 ms 11260 KB Output is correct
6 Correct 83 ms 11260 KB Output is correct
7 Correct 122 ms 11352 KB Output is correct
8 Correct 121 ms 11256 KB Output is correct
9 Correct 87 ms 11396 KB Output is correct
10 Correct 81 ms 11324 KB Output is correct
11 Correct 118 ms 13052 KB Output is correct
12 Correct 148 ms 13628 KB Output is correct
13 Correct 109 ms 13308 KB Output is correct
14 Correct 109 ms 12852 KB Output is correct

Subtask #3
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 6352 KB Output is correct
2 Correct 22 ms 7872 KB Output is correct
3 Correct 36 ms 9184 KB Output is correct
4 Correct 69 ms 17720 KB Output is correct
5 Correct 84 ms 17716 KB Output is correct
6 Correct 62 ms 17720 KB Output is correct
7 Correct 66 ms 17696 KB Output is correct
8 Correct 93 ms 17792 KB Output is correct
9 Correct 84 ms 17716 KB Output is correct

Subtask #4
33.0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 5072 KB Output is correct
2 Correct 12 ms 5588 KB Output is correct
3 Correct 83 ms 9892 KB Output is correct
4 Correct 94 ms 11296 KB Output is correct
5 Correct 109 ms 11324 KB Output is correct
6 Correct 102 ms 11244 KB Output is correct
7 Correct 102 ms 11324 KB Output is correct
8 Correct 90 ms 11296 KB Output is correct
9 Correct 118 ms 11264 KB Output is correct
10 Correct 91 ms 11332 KB Output is correct
11 Correct 81 ms 12188 KB Output is correct
12 Correct 107 ms 13320 KB Output is correct
13 Correct 124 ms 12860 KB Output is correct
14 Correct 87 ms 13252 KB Output is correct
15 Correct 88 ms 11252 KB Output is correct
16 Correct 99 ms 11324 KB Output is correct
17 Correct 115 ms 12556 KB Output is correct
18 Correct 130 ms 12928 KB Output is correct
19 Correct 127 ms 11328 KB Output is correct
20 Correct 108 ms 13744 KB Output is correct
21 Correct 96 ms 11512 KB Output is correct
22 Correct 74 ms 11600 KB Output is correct
23 Correct 73 ms 11536 KB Output is correct
24 Correct 93 ms 12076 KB Output is correct
25 Correct 95 ms 17012 KB Output is correct

Subtask #5
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 6096 KB Output is correct
2 Correct 16 ms 6236 KB Output is correct
3 Correct 115 ms 15352 KB Output is correct
4 Correct 134 ms 15932 KB Output is correct
5 Correct 174 ms 17196 KB Output is correct
6 Correct 152 ms 17188 KB Output is correct
7 Correct 133 ms 17176 KB Output is correct
8 Correct 171 ms 17228 KB Output is correct
9 Correct 165 ms 13760 KB Output is correct
10 Correct 114 ms 14212 KB Output is correct
11 Correct 147 ms 14976 KB Output is correct
12 Correct 159 ms 16280 KB Output is correct
13 Correct 154 ms 16744 KB Output is correct
14 Correct 179 ms 17192 KB Output is correct
15 Correct 130 ms 17244 KB Output is correct
16 Correct 127 ms 15060 KB Output is correct
17 Correct 84 ms 15328 KB Output is correct
18 Correct 101 ms 15584 KB Output is correct
19 Correct 112 ms 15472 KB Output is correct
20 Correct 82 ms 15524 KB Output is correct
21 Correct 127 ms 17168 KB Output is correct

Subtask #6
0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 6096 KB Output is correct
2 Correct 12 ms 6204 KB Output is correct
3 Correct 125 ms 15524 KB Output is correct
4 Incorrect 124 ms 15632 KB Output is incorrect: {s, t} is wrong.
5 Halted 0 ms 0 KB -