제출 #744996

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
744996		arush_agu	자매 도시 (APIO20_swap)	C++17	50 / 100	2053 ms	27060 KiB

swap

#include <algorithm>
#include <cctype>
#include <cmath>
#include <cstdio>
#include <cstring>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <functional>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <vector>

#ifdef DEBUG
#include <time.h>
#endif

#define all(a) (a).begin(), (a).end()
#define rev(a) (a).rbegin(), (a).rend()
#define F first
#define S second
int recur_depth = 0;
#ifdef DEBUG
#define dbg(x)                                                                 \
  {                                                                            \
    ++recur_depth;                                                             \
    auto x_ = x;                                                               \
    --recur_depth;                                                             \
    cerr << string(recur_depth, '\t') << "\e[91m" << __func__ << ":"           \
         << __LINE__ << "\t" << #x << " = " << x_ << "\e[39m" << endl;         \
  }
#else
#define dbg(x)
#endif

using namespace std;
using namespace __gnu_pbds;

typedef pair<int, int> ii;

typedef long long ll;
typedef long double ld;
typedef pair<ll, ll> llll;

typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<pair<int, int>> vii;
typedef vector<vii> vvii;

typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<pair<ll, ll>> vll;
typedef vector<vll> vvll;

typedef vector<bool> vb;

template <class type1>
using ordered_set = tree<type1, null_type, less<type1>, rb_tree_tag,
                         tree_order_statistics_node_update>;

template <typename A, typename B>
ostream &operator<<(ostream &os, const pair<A, B> &p) {
  return os << '(' << p.first << ", " << p.second << ')';
}
template <typename T_container, typename T = typename enable_if<
                                    !is_same<T_container, string>::value,
                                    typename T_container::value_type>::type>
ostream &operator<<(ostream &os, const T_container &v) {
  os << '{';
  string sep;
  for (const T &x : v)
    os << sep << x, sep = ", ";
  return os << '}';
}

const ll MOD = 1e9 + 7;
// const ll MOD = 998244353;
const ll INF = 1e9;
const ld EPS = 1e-9;

int n, m;
vl u, v, w;
vvll adj;

bool sub1 = 0;
int mx_w;

bool sub2 = 0;
vll w_sort;

struct DSU {
  int nn;
  vi par, sz;

  void init(int nnn) {
    nn = nnn;
    par = vi(nn, -1); sz = vi(nn, 1);
  }

  int find(int x) {
    if (par[x] == -1) return x;
    return par[x] = find(par[x]);
  }

  void merge(int x, int y) {
    x = find(x); y = find(y);
    if (x == y) return;
    if (sz[x] < sz[y]) swap(x, y);
    par[y] = x;
    sz[x] += sz[y];
  }
} dsu;

void init(int nn, int mm, vi uu, vi vv, vi ww) {
  n = nn, m = mm;
  for (int &x : uu) u.push_back(x);
  for (int &x : vv) v.push_back(x);
  for (int &x : ww) w.push_back(x);
  adj = vvll(n);
  for (int i=0; i<m; i++) {
    adj[u[i]].push_back({v[i], w[i]});
    adj[v[i]].push_back({u[i], w[i]});
  }

  dsu.init(n);

  sub1 = 1;
  for (int i=0; i<m; i++) if (adj[i].size() > 2) {
    sub1 = 0; break;
  }
  if (sub1) mx_w = *max_element(all(w));

  sub2 = 1;
  if (m != n - 1) sub2 = 0;
  for (int i=0; i<m; i++) if (u[i] != 0) {
    sub2 = 0;
    break;
  }
  if (sub2) {
    w_sort = vll(m); for (int i=0; i<m; i++) w_sort[i] = {w[i], v[i]};
    sort(all(w_sort));
  }
}

int getMinimumFuelCapacity(int x, int y) {
  if (sub1) {
    if (m == n - 1) return -1;
    assert(m == n);
    return mx_w;
  }

  if (sub2) {
    if (x > y) swap(x, y);
    if (x == 0) {
      if (y == w_sort[0].second || y == w_sort[1].second)
        return w_sort[2].first;
      return max(adj[y][0].second, w_sort[1].first);
    }

    if (adj[x][0].second > adj[y][0].second) swap(x, y);
    if (w_sort[0].first == adj[x][0].second && w_sort[1].first == adj[y][0].second) return w_sort[2].first;
    return adj[y][0].second;
  }

  auto check = [&](int mid) {
    for (int i=0; i<n; i++) dsu.par[i] = -1, dsu.sz[i] = 1;
    vi deg(n);
    for (int i=0; i<m; i++) if (w[i] <= mid) {
      dsu.merge(u[i], v[i]);
      deg[u[i]]++, deg[v[i]]++;
    }

    if (dsu.find(x) != dsu.find(y)) return 0;

    int cnt = 0;
    int cnt_1deg = 0, cnt_2deg = 0;
    for (int i=0; i<n; i++) if (dsu.find(x) == dsu.find(i)) {
      cnt++;
      if (deg[i] == 1) cnt_1deg++;
      if (deg[i] == 2) cnt_2deg++;
    }

    if (cnt_1deg == 2 && cnt_2deg == cnt - 2) return 0;
    return 1;
  };

  ll l = 1, r = INF, ans = INF;
  while (l <= r) {
    ll mid = (l + r) / 2;
    if (check(mid)) {
      ans = mid;
      r = mid - 1;
    } else l = mid + 1;
  }
  return ans;
}

#ifdef DEBUG
void solve() {
  int n, m; cin >> n >> m;
  vi u(m), v(m), w(m);
  for (int i=0; i<m; i++) {
    cin >> u[i] >> v[i] >> w[i];
  }

  init(n, m, u, v, w);

  int q; cin >> q;
  while (q--) {
    int x, y; cin >> x >> y;
    cout << getMinimumFuelCapacity(x, y) << "\n";
  }
}

int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(NULL);

  clock_t start = clock();

  int test_cases = 1;
  /* cin >> test_cases; */

  while (test_cases--)
    solve();

  cerr << fixed << setprecision(10)
       << "\nTime Taken: " << (double)(clock() - start) / CLOCKS_PER_SEC
       << "s\n";
  return 0;
}
#endif

• Subtask 1: 6 / 6
• Subtask 2: 7 / 7
• Subtask 3: 17 / 17
• Subtask 4: 20 / 20
• Subtask 5: 0 / 23
• Subtask 6: 0 / 27