Submission #1045666

#	Time	Username	Problem	Language	Result	Execution time	Memory
1045666		mychecksedad	Street Lamps (APIO19_street_lamps)	C++17	0 / 100	20 ms	9160 KiB

street_lamps

/* Author : Mychecksdead  */
#include<bits/stdc++.h>
using namespace std;
#define ll long long int
#define MOD (1000000000+7)
#define MOD1 (998244353)
#define pb push_back
#define all(x) x.begin(), x.end()
#define en cout << '\n'
#define ff first
#define ss second
const int N = 1e6+100, M = 1e5+10, K = 52, MX = 30;


struct Dsu {
  vector<int> s, p;
  vector<pair<int,int>> poop;
  int sz;
  Dsu(int n){
    sz = n;
    s.resize(n+1, 1);
    p.resize(n+1);
    for(int i = 0; i <= n; ++i) p[i] = i;
  }
  int find(int v){
    if(p[v] == v) return v;
    return find(p[v]);
  }
  void merge(int a, int b){
    a = find(a);
    b = find(b);
    
    if(a != b){
      if(s[a] > s[b]){
        swap(a, b);
      }
      s[b] += s[a];
      p[a] = b;
      poop.pb({a, b});      
    }else{
      poop.pb({-1, -1
  });
    }
  }
  void rollback(){
    if(poop.size() == 0) return;
    if(poop.back().ff == -1){
      poop.pop_back();
      return;
    }
    int a = poop.back().ff;
    int b = poop.back().ss;
    poop.pop_back();
    p[a] = a;
    s[b] -= s[a];
  }
};


int n, m, q;
vector<array<int, 4>> edges;
int S = 300;
void solve(){
  cin >> n >> m;
  for(int i = 0; i < m; ++i){
    int u, v, w; cin >> u >> v >> w;
    edges.pb({w, v, u, i});
  }
  sort(all(edges), greater<array<int, 4>>());
  vector<int> pos(m);
  
  vector<int> used(m);
  cin >> q;
  int pu = 0;
  for(int y = 0; y < q; y += S){
    for(int i = 0; i < m; ++i) pos[edges[i][3]] = i;
    int k = min(q, y+S) - y;
    vector<array<int, 3>> upd;
    vector<array<int, 4>> qr;
    int qq = 0;
    for(int j = 0; j < k; ++j){
      int t, u, v; cin >> t >> u >> v;
      if(t == 1){
        --u;
        upd.pb({v, u, j});
      }else{
        qr.pb({v, u, j, qq++});
      }
    }
    vector<int> ans(qq);

    Dsu d(n);

    // sort(all(upd), greater<array<int, 3>>());
    sort(all(qr), greater<array<int, 4>>());
   
    int pu = 0;
    for(int l = 0; l < upd.size(); ++l) used[upd[l][1]] = 1;
      // for(auto f: qr){
      //   cout << f[0] << ' ' << f[1] << ' ' << f[2] << '\n';
      // }

    for(int j = 0; j < qq; ++j){
      int w = qr[j][0];
      // cout << w << " : q\n" ;
      while(pu < edges.size() && edges[pu][0] >= w){
        if(used[edges[pu][3]]) ++pu;
        else{
          d.merge(edges[pu][1], edges[pu][2]);
          // cout << edges[pu][3] << " : upd" << '\n';
          ++pu;
        }
      }

      int roll = 0;
      for(int l = int(upd.size()) - 1; l >= 0; --l){
        int idx = upd[l][1];
        if(used[idx] > 1) continue;
        if(upd[l][2] < qr[j][2]){
          used[idx] = l + 2;
        }
      }
      for(int l = int(upd.size()) - 1; l >= 0; --l){
        int idx = upd[l][1];
        if(!(used[idx] == 1 || used[idx] == l + 2)) continue;
        if(upd[l][2] < qr[j][2]){
          if(upd[l][0] >= w){
            ++roll;
            d.merge(edges[pos[idx]][1], edges[pos[idx]][2]);
          }
        }else{
          if(edges[pos[idx]][0] >= w){
            ++roll;
            d.merge(edges[pos[idx]][1], edges[pos[idx]][2]);
          }
        }
      }
      for(int l = int(upd.size()) - 1; l >= 0; --l){
        int idx = upd[l][1];
        used[idx] = 1;
      }
      // cout << qr[j][1] << ' ';
      ans[qr[j][3]] = d.s[d.find(qr[j][1])];
      for(int l = 0; l < roll; ++l){
        d.rollback();
      }
    }
    for(int l = 0; l < upd.size(); ++l) used[upd[l][1]] = 0;


    for(auto x: ans) cout << x << '\n';
  
    for(auto p: upd){
      edges[pos[p[1]]][0] = p[0];
    }
    sort(all(edges), greater<array<int, 4>>());
  }
}


int main(){
  cin.tie(0); ios::sync_with_stdio(0);
  int tt = 1, aa;
  // freopen("in.txt", "r", stdin);
  // freopen("out.txt", "w", stdout);
  while(tt--){
    solve();
    en;
  }
  cerr<<"time taken : "<<(float)clock()/CLOCKS_PER_SEC<<" seconds\n";
  return 0;
} 

Compilation message (stderr)

street_lamps.cpp: In function 'void solve()':
street_lamps.cpp:98:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::array<int, 3> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   98 |     for(int l = 0; l < upd.size(); ++l) used[upd[l][1]] = 1;
      |                    ~~^~~~~~~~~~~~
street_lamps.cpp:106:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::array<int, 4> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  106 |       while(pu < edges.size() && edges[pu][0] >= w){
      |             ~~~^~~~~~~~~~~~~~
street_lamps.cpp:148:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::array<int, 3> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  148 |     for(int l = 0; l < upd.size(); ++l) used[upd[l][1]] = 0;
      |                    ~~^~~~~~~~~~~~
street_lamps.cpp:74:7: warning: unused variable 'pu' [-Wunused-variable]
   74 |   int pu = 0;
      |       ^~
street_lamps.cpp: In function 'int main()':
street_lamps.cpp:163:15: warning: unused variable 'aa' [-Wunused-variable]
  163 |   int tt = 1, aa;
      |               ^~

• Subtask 1: 0 / 20
• Subtask 2: 0 / 20
• Subtask 3: 0 / 20
• Subtask 4: 0 / 20
• Subtask 5: 0 / 20