Submission #570603

#	Time	Username	Problem	Language	Result	Execution time	Memory
570603		Sam_a17	Evacuation plan (IZhO18_plan)	C++14	100 / 100	874 ms	51500 KiB

plan

#define _CRT_SECURE_NO_WARNINGS
#include <bits/stdc++.h>
//#include "temp.cpp"
#include <cstdio>
using namespace std;

#ifndef ONLINE_JUDGE
#define dbg(x) cerr << #x <<" "; print(x); cerr << endl;
#else
#define dbg(x)
#endif

#define sz(x) (int((x).size()))
#define len(x) (int)x.length()
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define clr(x) (x).clear()
#define uniq(x) x.resize(unique(all(x)) - x.begin());
#define blt __builtin_popcount

#define pb push_back
#define popf pop_front
#define popb pop_back

void print(long long t) {cerr << t;}
void print(int t) {cerr << t;}
void print(string t) {cerr << t;}
void print(char t) {cerr << t;}
void print(double t) {cerr << t;}
void print(long double t) {cerr << t;}
void print(unsigned long long t) {cerr << t;}

template <class T, class V> void print(pair <T, V> p);
template <class T> void print(vector <T> v);
template <class T> void print(set <T> v);
template <class T, class V> void print(map <T, V> v);
template <class T> void print(multiset <T> v);
template <class T, class V> void print(T v[],V n) {cerr << "["; for(int i = 0; i < n; i++) {print(v[i]); cerr << " "; } cerr << "]";}
template <class T, class V> void print(pair <T, V> p) {cerr << "{"; print(p.first); cerr << ","; print(p.second); cerr << "}";}
template <class T> void print(vector <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T> void print(set <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T> void print(multiset <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T, class V> void print(map <T, V> v) {cerr << "[ "; for (auto i : v) {print(i); cerr << " ";} cerr << "]";}

#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
#define nl '\n'

// for grid problems
int dx[8] = {-1,0,1,0,1,-1,1,-1};
int dy[8] = {0,1,0,-1,1,1,-1,-1};

// lowest / (1 << 17) >= 1e5 / (1 << 18) >= 2e5 / (1 << 21) >= 1e6
void fastIO() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr); cout.tie(nullptr);
}
// file in/out
void setIO(string str = "") {
  fastIO();

  if (str != "") {
    freopen((str + ".in").c_str(), "r", stdin);
    freopen((str + ".out").c_str(), "w", stdout);
  }
}
// Indexed Set
template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
const long long N = 2e5 + 10, inf = 1e15, LOG = 22;
long long n, m, k, A[N], dist[N], p[N], sz[N], depth[N], top[N], id[N];
vector<pair<long long, long long>> adj[N];
vector<long long> t[N];

// Range Queries
struct segTree {
  // 0 indexed
  // [l: r + 1]

  // for 1 index
  // [l - 1: r]
  vector<long long> mTree;
  int size;

  void init(long long n) {
    size = 1;
    while(size < n)  {
      size *= 2;
    }
    mTree.assign(2 * size - 1, INT64_MAX);
  }

  void upd(int u, long long v, int x, int lx, int rx) { // set value at pos u
    if(rx - lx == 1) {
      mTree[x] = v;
      return;
    }

    int m = (lx + rx) / 2;
    if(u < m) {
      upd(u, v, 2 * x + 1, lx, m);
    }else {
      upd(u, v, 2 * x + 2, m, rx);
    }
    mTree[x] = min(mTree[2 * x + 1], mTree[2 * x + 2]);
  }

  void upd(int u, long long v) {
    upd(u, v, 0, 0, size);
  }

  long long qry (long long l, long long  r, int x, int lx, int rx) { // range queries
    if(l >= rx || lx >= r) {
      return INT64_MAX;
    }
    if(lx >= l && r >= rx) {
      return mTree[x];
    }

    int m = (rx + lx) / 2;
    long long s1 = qry(l, r, 2 * x + 1, lx, m);
    long long s2 = qry(l, r, 2 * x + 2, m, rx);
    return min(s1, s2);
  }

  long long qry(long long l, long long r) {
    return qry(l, r, 0,0,size);
  }
};

segTree seg;

long long  dfs_sz(int node, int parent) {
  sz[node] = 1, p[node] = parent;
  for(auto u: t[node]) {
    if(u == parent) continue;
    depth[u] = depth[node] + 1;
    sz[node] += dfs_sz(u, node);
  }
  return sz[node];
}

long long it = 1;

void dfs_hld(int node, int parent, int tp) {
  id[node] = it++, top[node] = tp;
  seg.upd(id[node], dist[node]);
  int heavy_child = -1, heavy_size = -1;
  for(auto u: t[node]) {
    if(u == parent) continue;
    if(sz[u] > heavy_size) {
      heavy_size = sz[u];
      heavy_child = u;
    }
  }

  if(heavy_child == -1) {
    return;
  }

  dfs_hld(heavy_child, node, tp);
  for(auto u: t[node]) {
    if(u == parent || u == heavy_child) continue;
    dfs_hld(u, node, u);
  }
}

long long  path(int x, int y) {
  long long answ = INT64_MAX;
  while(top[x] != top[y]) {
    if(depth[top[x]] < depth[top[y]]) {
      swap(x, y);
    }
    answ = min(answ, seg.qry(id[top[x]], id[x] + 1));
    x = p[top[x]];
  }
  if(depth[x] > depth[y]) {
    swap(x, y);
  }
  answ = min(answ, seg.qry(id[x], id[y] + 1));
  return answ;
}

void djik() {
  vector<bool> used(n + 1);
  priority_queue<pair<long long, long long>> q;

  for(int i = 1; i <= n; i++) {
    dist[i] = inf;
  }

  for(int i = 1; i <= k; i++) {
    dist[A[i]] = 0;
    q.push({0, A[i]});
  }

  while(!q.empty()) {
    auto u = q.top();
    q.pop();

    if(used[u.second]) {
      continue;
    }
    used[u.second] = true;

    for(auto i: adj[u.second]) {
      if(dist[i.first] > dist[u.second] + i.second) {
        dist[i.first] = dist[u.second] + i.second;
        q.push({-dist[i.first], i.first});
      }
    }
  }
}

int find(int a) {
  if(a != p[a]) {
    p[a] = find(p[a]);
  }
  return p[a];
}

int merge(int a, int b) {
  a = find(a), b = find(b);
  if(a == b) {
    return 0;
  }
  if(sz[a] > sz[b]) {
    swap(a, b);
  }
  p[b] = a, sz[a] += sz[b];
  return 1;
}


bool cmp(pair<long long, long long> a,pair<long long, long long> b) {
  if(dist[a.first] > dist[b.first]) {
    return true;
  } else {
    return false;
  }
}

void solve_() {
  scanf("%lld%lld", &n, &m);

  for(int i = 1; i <= n; i++) {
    p[i] = i, sz[i] = 1;
  }

  for(int i = 1; i <= m; i++) {
    long long a, b, c;
    scanf("%lld%lld%lld", &a, &b, &c);
    adj[a].push_back({b, c});
    adj[b].push_back({a, c});
  }

  scanf("%lld", &k);

  for(int i = 1; i <= k; i++) {
    scanf("%lld", &A[i]);
  }

  djik();

  vector<pair<long long, long long>> dists;

  for(int i = 1; i <= n; i++) {
    dists.push_back({dist[i], i});
  }

  sort(rall(dists));

  vector<bool> contain(n + 1);
  for(int i = 0; i < n; i++) {
    contain[dists[i].second] = true;

    sort(all(adj[dists[i].second]), cmp);

    for(auto j: adj[dists[i].second]) {
      if(contain[j.first] && merge(j.first, dists[i].second)) {
        t[j.first].push_back(dists[i].second);
        t[dists[i].second].push_back(j.first);
      }
    }
  }

  seg.init(n + 1);

  dfs_sz(1, 0);
  dfs_hld(1, 0, 1);

  int q; scanf("%d", &q);

  while(q--) {
    int a, b; scanf("%d%d", &a, &b);
    printf("%lld\n", path(a, b));
  }
}


int main() {
  setIO();

  auto solve = [&](int test_case)-> void {
    while(test_case--) {
      solve_();
    }
  };

  int test_cases = 1;
  solve(test_cases);

  return 0;
}

Compilation message (stderr)

plan.cpp: In function 'void setIO(std::string)':
plan.cpp:63:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   63 |     freopen((str + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
plan.cpp:64:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   64 |     freopen((str + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
plan.cpp: In function 'void solve_()':
plan.cpp:243:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  243 |   scanf("%lld%lld", &n, &m);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~
plan.cpp:251:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  251 |     scanf("%lld%lld%lld", &a, &b, &c);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
plan.cpp:256:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  256 |   scanf("%lld", &k);
      |   ~~~~~^~~~~~~~~~~~
plan.cpp:259:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  259 |     scanf("%lld", &A[i]);
      |     ~~~~~^~~~~~~~~~~~~~~
plan.cpp:291:15: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  291 |   int q; scanf("%d", &q);
      |          ~~~~~^~~~~~~~~~
plan.cpp:294:20: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  294 |     int a, b; scanf("%d%d", &a, &b);
      |               ~~~~~^~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 13 / 13
• Subtask 3: 12 / 12
• Subtask 4: 19 / 19
• Subtask 5: 46 / 46