Submission #771842

#	Time	Username	Problem	Language	Result	Execution time	Memory
771842		Sam_a17	New Home (APIO18_new_home)	C++17	0 / 100	25 ms	38484 KiB

new_home

#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
#define ld long double
#define ll long long
 
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;}
 
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
#define nl '\n'
 
// Indexed Set  
template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
 
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(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> void print(Tree <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 << "]";}
template <class T> void print(deque <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
 
 
// for random generations
mt19937 myrand(chrono::steady_clock::now().time_since_epoch().count());
// mt19937 myrand(131);
 
// 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 == "input") {
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
  } else if(str != "") {
    freopen((str + ".in").c_str(), "r", stdin);
    freopen((str + ".out").c_str(), "w", stdout);
  }
}

const int N = 2e5 + 10;
vector<int> adj[N], comps[N];
vector<pair<int, int>> adj2[N];
bool vis[N], vis2[N];
int dp[51][51][51];
long long n, m, ans, n2;
int st, tin[N], tout[N], timer;
int low[N], comp[N], sz_comp[N];

set<pair<int, int>> mp;
void IS_BRIDGE(int a, int b) {
  mp.insert({a, b});
  mp.insert({b, a});
}

void dfs(int v, int p = -1) {
  vis[v] = true;
  tin[v] = low[v] = timer++;
  for (int to : adj[v]) {
      if (to == p) continue;
      if (vis[to]) {
          low[v] = min(low[v], tin[to]);
      } else {
          dfs(to, v);
          low[v] = min(low[v], low[to]);
          if (low[to] > tin[v]) {
              IS_BRIDGE(v, to);
          }
      }
  }
}

void dfs_gen(int node) {
  vis[node] = true;
  comps[st].push_back(node);
  for(auto i: adj[node]) {
    pair<int, int> edge = {i, node};

    if(mp.find(edge) != mp.end()) {
      if(comp[i]) {
        adj2[st].push_back({comp[i], i});
        adj2[comp[i]].push_back({st, i});
      }
      continue;
    }
    if(vis[i]) continue;

    comp[i] = st;
    sz_comp[i]++;
    dfs_gen(i);
  }
}

long long sub[N];
void dfsik(int node, int parent) {
  vis[node] = true;
  sub[node] = sz(comps[node]);
  for(auto i: adj2[node]) {
    if(i.first == parent) continue;
    dfsik(i.first, node);
    sub[node] += sub[i.first];
  }
}

long long cur_al = 0, answ = 0;

vector<long long> have[N];
long long val[N];
vector<long long> whi;

void dfs1(int node, int parent) {
  vector<long long> child;
  if(sub[node] != cur_al) {
    long long vle = cur_al - sub[node];;
    for(auto i: adj2[node]) {
      if(i.first == parent) {
        have[i.second].push_back(vle);
        val[i.second] += vle;
        whi.push_back(i.second);
      }
    }
  }
  

  for(auto i: adj2[node]) {
    if(i.first == parent) continue;
    if(sz(have[i.second])) {
      have[i.second].push_back(sub[i.first]);
      val[i.second] += sub[i.first];
    } else {
      have[i.second].push_back(sub[i.first]);
      val[i.second] += sub[i.first];
      whi.push_back(i.second);
    }
  }

  long long sum = cur_al - sz(comps[node]);
  long long add = 0;
  for(auto i: whi) {
    long long bu = val[i];
    long long cmp = sz(comps[node]);
    answ += 2ll * (sum - bu) * bu * cmp;
    add += 2ll * (sum - bu) * bu * cmp;
    sum -= bu;
  }


  if(sz(comps[node]) != 1) {
    for(auto i: whi) {
      long long bu = val[i];
      long long cmp = sz(comps[node]);
      answ += 2ll * bu * (cmp - 1);
      answ += 2ll * bu * (cmp - 1) * (cmp - 2); 
      // add += 2ll * bu * (cmp - 1);
      // add += 2ll * bu* (cmp - 1) * (cmp - 2); 
    }
  }

  for(auto i: whi) {
    sum = val[i];
    for(auto j: have[i]) {
      answ += 2 * (sum - j) * j;
      sum -= j;
    }

    val[i] = 0;
    have[i].clear();
  }
  whi.clear();
  
  for(auto i: adj2[node]) {
    if(i.first == parent) continue;
    dfs1(i.first, node);
  }
}

long long c_n(long long x) {
  if(x < 2) return 0;
  return x * (x - 1);
}

void solve_() {
  cin >> n >> m;

  for(int i = 1; i <= m; i++) {
    int a, b; cin >> a >> b;
    adj[a].push_back(b);
    adj[b].push_back(a);
  }

  for(int i = 1; i <= n; i++) {
    low[i] = tin[i] = -1;
  }
  for(int i = 1; i <= n; i++) {
    if(vis[i]) continue;
    dfs(i, 0);
  }

  memset(vis, 0, sizeof(vis));

  for(int i = 1; i <= n; i++) {
    if(!vis[i]) {
      st = i;
      comp[i] = st;
      sz_comp[i]++;
      dfs_gen(i);
    }
  }

  for(int i = 1; i <= n; i++) {
    sort(all(adj2[i]));
    uniq(adj2[i]);
  }

  for(int i = 1; i <= n; i++) {
    if(comp[i] == i) {
      for(auto j: comps[i]) {
        ans += c_n(sz(comps[i]) - 1);
      }
    }
  }


  memset(vis, 0, sizeof(vis));

  for(int i = 1; i <= n; i++) {
    if(vis[comp[i]]) continue;
    dfsik(i, 0);

    cur_al = sub[i];
    dfs1(i, 0);
  }
  cout << ans + answ << '\n';
}
 
int main() {
  setIO();
 
  auto solve = [&](int test_case)-> void {
    for(int i = 1; i <= test_case; i++) {
      solve_();
    }
  };
 
  int test_cases = 1;
  // cin >> test_cases;
  solve(test_cases);
 
  return 0;
} 

Compilation message (stderr)

new_home.cpp: In function 'void solve_()':
new_home.cpp:260:16: warning: unused variable 'j' [-Wunused-variable]
  260 |       for(auto j: comps[i]) {
      |                ^
new_home.cpp: In function 'void setIO(std::string)':
new_home.cpp:76:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   76 |     freopen("input.txt", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
new_home.cpp:77:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   77 |     freopen("output.txt", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
new_home.cpp:79:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   79 |     freopen((str + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
new_home.cpp:80:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   80 |     freopen((str + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 7
• Subtask 3: 0 / 10
• Subtask 4: 0 / 23
• Subtask 5: 0 / 35
• Subtask 6: 0 / 20