Submission #669571

#	Time	Username	Problem	Language	Result	Execution time	Memory
669571		Iliya_	Pipes (CEOI15_pipes)	C++17	0 / 100	921 ms	65536 KiB

pipes

// IN THE NAME OF GOD
#include<bits/stdc++.h>
#pragma GCC optimize ("O2,unroll-loops")
#define endl '\n';
#define file_reading freopen("input.txt", "r", stdin); freopen("output.txt", "w", stdout);
using namespace std;
typedef long long ll;
typedef long double dll;
typedef unsigned long long ull;
// Variables
const int B = 1e5+7;
const int BB = 6e6+7;;
pair<int,int> v[BB];
int par1[B];
int siz1[B];
int par2[B];
int siz2[B];
int n,m,a,b,one,two,u;
vector<pair<int,int>> g[B];
bitset<B> seen;
bool ans[BB];
pair<int,int> dat[B];
int father[B];
int val[B];
// main functions
int get_root1(int v){
     return (par1[v] == v ? v : par1[v] = get_root1(par1[v]));
}
int get_root2(int v){
     return (par2[v] == v ? v : par2[v] = get_root2(par2[v]));
}
bool merge1(int v, int u){
     one = get_root1(v);
     two = get_root1(u);
     if (one == two){return 0;}
     if (siz1[one] > siz1[two]){swap(one,two);}
     siz1[two] += siz1[one];
     par1[one] = two;
     return 1;
}
bool merge2(int v, int u){
     one = get_root2(v);
     two = get_root2(u);
     if (one == two){return 0;}
     if (siz2[one] > siz2[two]){swap(one,two);}
     siz2[two] += siz2[one];
     par2[one] = two;
     return 1;
}
void dfs(int v){
     seen[v] = 1;
     vector<pair<int,int>> check;
     for(auto cur : g[v]){
          u = cur.first;
          if (seen[u] == 0){
               father[u] = v;
               check.push_back(cur);
               dfs(u);
          }
          else if (father[u] != v && father[v] != u){
               dat[v].first++;
               dat[u].second++;
          }
     }
     for(auto cur : check){
          u = cur.first;
          if (val[u] == 0){ans[cur.second] = 1;}
          dat[v].first += dat[u].first;
          dat[v].second += dat[u].second;
     }
     val[v] = dat[v].first - dat[v].second;
}
int32_t main(){
	ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);

	cin >> n >> m;
	for(int i=1; i<=n; i++){siz1[i] = siz2[i] = 1; par1[i] = par2[i] = i;}
	for(int i=1; i<=m; i++){
          cin >> v[i].first >> v[i].second;
          if (merge1(v[i].first,v[i].second)){
               g[v[i].first].push_back({v[i].second,i});
               g[v[i].second].push_back({v[i].first,i});
          }
          else if (merge2(v[i].first,v[i].second)){
               g[v[i].first].push_back({v[i].second,i});
               g[v[i].second].push_back({v[i].first,i});
          }
	}
     for(int i=1; i<=n; i++){
          if (seen[i] == 0){
               father[i] = 0;
               dfs(i);
          }
     }
     for(int i=1; i<=m; i++){
          if (ans[i]){
               cout << v[i].first << " " << v[i].second << endl;
          }
     }

	return 0;
}

• Subtask 1: 0 / 10
• Subtask 2: 0 / 10
• Subtask 3: 0 / 10
• Subtask 4: 0 / 10
• Subtask 5: 0 / 10
• Subtask 6: 0 / 10
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 10
• Subtask 10: 0 / 10