Submission #280138

#	Time	Username	Problem	Language	Result	Execution time	Memory
280138		ACmachine	Pipes (CEOI15_pipes)	C++17	40 / 100	1474 ms	65536 KiB

pipes

#include <bits/stdc++.h>
using namespace std;

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;

template<typename T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template<typename T, typename U> using ordered_map = tree<T, U, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

typedef long long ll;
typedef long double ld;
typedef double db;
typedef string str;

typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<pii> vpii;
typedef vector<pll> vpll;
typedef vector<str> vstr;

#define FOR(i,j,k,in) for(int i=(j); i < (k);i+=in)
#define FORD(i,j,k,in) for(int i=(j); i >=(k);i-=in)
#define REP(i,b) FOR(i,0,b,1)
#define REPD(i,b) FORD(i,b,0,1)
#define pb push_back 
#define mp make_pair
#define ff first
#define ss second
#define all(x) begin(x), end(x)
#define rsz resize 

const double EPS = 1e-9;
const int MOD = 1e9+7; // 998244353;
const ll INFF = 1e18;
const int INF = 1e9;
const ld PI = acos((ld)-1);
const vi dy = {1, 0, -1, 0, -1, 1, 1, -1};
const vi dx = {0, 1, 0, -1, -1, 1, -1, 1};

#ifdef DEBUG
#define DBG if(1)
#else
#define DBG if(0)
#endif

#define dbg(x) cout << "(" << #x << " : " << x << ")" << endl;
// ostreams
template <class T, class U>
ostream& operator<<(ostream& out, const pair<T, U> &par) {out << "[" << par.first << ";" << par.second << "]"; return out;}
template <class T>
ostream& operator<<(ostream& out, const set<T> &cont) { out << "{"; for( const auto &x:cont) out << x << ", "; out << "}"; return out; }
template <class T, class U>
ostream& operator<<(ostream& out, const map<T, U> &cont) {out << "{"; for( const auto &x:cont) out << x << ", "; out << "}"; return out; }
template<class T>
ostream& operator<<(ostream& out, const vector<T> &v){ out << "[";  REP(i, v.size()) out << v[i] << ", ";  out << "]"; return out;}
// istreams
template<class T>
istream& operator>>(istream& in, vector<T> &v){ for(auto &x : v) in >> x; return in; }
template<class T, class U>
istream& operator>>(istream& in, pair<T, U> &p){ in >> p.ff >> p.ss; return in; }
//searches
template<typename T, typename U>
T bsl(T lo, T hi, U f){ hi++; T mid; while(lo < hi){ mid = (lo + hi)/2; f(mid) ? hi = mid : lo = mid+1; } return lo; }
template<typename U>
double bsld(double lo, double hi, U f, double p = 1e-9){ int r = 3 + (int)log2((hi - lo)/p); double mid; while(r--){ mid = (lo + hi)/2; f(mid) ? hi = mid : lo = mid; } return (lo + hi)/2; }
template<typename T, typename U>
T bsh(T lo, T hi, U f){ lo--; T mid; while(lo < hi){ mid = (lo + hi + 1)/2; f(mid) ? lo = mid : hi = mid-1; } return lo; }
template<typename U>
double bshd(double lo, double hi, U f, double p = 1e-9){ int r = 3+(int)log2((hi - lo)/p); double mid; while(r--){ mid = (lo + hi)/2; f(mid) ? lo = mid : hi = mid; } return (lo + hi)/2; }
// some more utility functions
template<typename T>
pair<T, int> get_min(vector<T> &v){ typename vector<T> :: iterator it = min_element(v.begin(), v.end()); return mp(*it, it - v.begin());}
template<typename T>
pair<T, int> get_max(vector<T> &v){ typename vector<T> :: iterator it = max_element(v.begin(), v.end()); return mp(*it, it - v.begin());}        
template<typename T> bool ckmin(T& a, const T& b){return b < a ? a = b , true : false;}
template<typename T> bool ckmax(T& a, const T& b){return b > a ? a = b, true : false;}


//practically constant time - dsu with path compression
// if(e[x] < 0) e[x] is root and size is -e[x] else e[x] is parent of x;
// kactl icpc notebook
struct dsu{
    vector<int> e;
    dsu(){};
    dsu(int n){
        e.resize(n, -1);
    }
    int find(int x){ return (e[x] < 0 ? x : e[x] = find(e[x])); }
    int size(int x){ return -e[find(x)]; }
    int sameSet(int a, int b){ return find(a) == find(b); }
    bool join(int a, int b){
        a = find(a); b = find(b);
        if(a == b) return false;
        if(e[a] > e[b]) swap(a, b);
        e[a] += e[b]; e[b] = a;
        return true;
    }
};

vi in; vi low;
int t = 0;
void dfs(int v, int p, vector<vi> &adj){
    ++t; in[v] = t; low[v] = INF;
    map<int, int> cnt;
    for(auto x : adj[v]) cnt[x]++;
    for(auto x : adj[v]){
        if(x == p) continue;
        if(in[x] == -1){
            dfs(x, v, adj);
            if(low[x] > in[v] && cnt[x] < 2){
                cout << v+1 << " " << x+1 << endl;
            }
            low[v] = min(low[v], low[x]);
        }
        else if(in[v] > in[x]) low[v] = min(low[v], in[x]);
    }
}
struct AcAutomaton{
    int n, m;
    vector<vi> adj;
	void read_in(){
		cin >> n >> m;
        dsu comp(n); // connected components;
        dsu bcc(n); // biconnected components;
        adj.resize(n);
        in.resize(n, -1); low.resize(n);
        REP(i, m){
            int a, b; cin >> a >> b;
            --a; --b;
            bool discard = true;
            if(!comp.sameSet(a,b)){
                comp.join(a,b);
                discard = false;
            }
            else if(!bcc.sameSet(a, b)){
                bcc.join(a,b);
                discard = false;
            }
            if(!discard){
                adj[a].pb(b);
                adj[b].pb(a);
            }
        }
	} 
	void solve(){
		REP(i, n)
            if(in[i] == -1) dfs(i, -1, adj);
	}
};
    
int main(){
 	ios_base::sync_with_stdio(false);
 	cin.tie(NULL); cout.tie(NULL);
	int tcase = 1;
	while(tcase--){
		AcAutomaton solver;
		solver.read_in();
		solver.solve();
	}
    return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 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