Submission #212791

#	Time	Username	Problem	Language	Result	Execution time	Memory
212791		WLZ	Chameleon's Love (JOI20_chameleon)	C++14	100 / 100	75 ms	504 KiB

chameleon

#include "chameleon.h"
#include <bits/stdc++.h>
using namespace std;
 
namespace {
  vector< vector<int> > g;
  vector<int> found, st;

  int check(vector<int> v, int cur) {
    v.push_back(cur);
    return (Query(v) < (int) v.size());
  }

  void find(vector<int>& v, int cur) {
    while (check(v, cur)) {
      int lo = 0, hi = (int) v.size() - 1;
      while (lo < hi) {
        int mid = (lo + hi) / 2;
        if (check(vector<int>(v.begin(), v.begin() + mid + 1), cur)) {
          hi = mid;
        } else {
          lo = mid + 1;
        }
      }
      found.push_back(v[lo]);
      v = vector<int>(v.begin() + lo + 1, v.end());
    }
  }
}
 
void dfs(int u) {
  for (auto& v : g[u]) {
    if (st[v] == -1) {
      st[v] = !st[u];
      dfs(v);
    }
  }
}

void Solve(int N) {
  g.resize(2 * N + 1);
  st.resize(2 * N + 1);
  st[1] = 0;
  for (int i = 1; i <= 2 * N; i++) {
    found.clear();
    st.assign(2 * N + 1, -1);
    for (int j = 1; j < i; j++) {
      if (st[j] == -1) {
        st[j] = 0;
        dfs(j);
      }
    }
    vector<int> a, b;
    for (int j = 1; j < i; j++) {
      if (st[j] == 0) {
        a.push_back(j);
      } else {
        b.push_back(j);
      }
    }
    find(a, i);
    find(b, i);
    if (found.empty()) {
      st[i] = 0;
    } else {
      for (auto& x : found) {
        st[i] = !st[x];
        g[i].push_back(x);
        g[x].push_back(i);
      }
    }
  }
  vector<int> used(2 * N + 1, 0), in(2 * N + 1, -1), out(2 * N + 1, -1);
  for (int i = 1; i <= 2 * N; i++) {
    if ((int) g[i].size() == 1) {
      continue;
    }
    if (Query({i, g[i][0], g[i][1]}) == 1) {
      out[i] = g[i][2];
      in[g[i][2]] = i;
    } else if (Query({i, g[i][0], g[i][2]}) == 1) {
      out[i] = g[i][1];
      in[g[i][1]] = i;
    } else {
      out[i] = g[i][0];
      in[g[i][0]] = i;
    }
  }
  for (int i = 1; i <= 2 * N; i++) {
    if (used[i]) {
      continue;
    }
    for (auto& x : g[i]) {
      if (x != in[i] && x != out[i]) {
        Answer(i, x);
        used[i] = used[x] = 1;
      }
    }
  }
}

• Subtask 1: 4 / 4
• Subtask 2: 20 / 20
• Subtask 3: 20 / 20
• Subtask 4: 20 / 20
• Subtask 5: 36 / 36