Submission #286964

#	Time	Username	Problem	Language	Result	Execution time	Memory
286964		ACmachine	철인 이종 경기 (APIO18_duathlon)	C++17	0 / 100	1117 ms	1048580 KiB

count_triplets

#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;}

// centroid decomposition of a biconnected component tree dafuq
// first only centoid decomp to pass those subtasks

template<typename T>
struct edge{
    int src;
    int dest;
    T cost;
};
template<typename T>
class graph{
    public: 
    vector<edge<T>> edges;
    vector<vector<int>> adj;
    int n;
    graph(){};
    graph(int _n){
        n = _n;
        adj.resize(n);
    }
};

template<typename T>
class undigraph : public graph<T>{
    public:
        using graph<T>::edges;
        using graph<T>::adj;
        using graph<T>::n;
        undigraph() : graph<T>(){};
        undigraph(int _n) : graph<T>(_n){};

        int add_edge(int src, int dest, T cost = 1){
            int id = edges.size();
            edges.push_back({src, dest, cost});
            adj[src].push_back(id);
            adj[dest].push_back(id);
            return id;
        }
};
int OneCentroid(int root, graph<int> &g, vector<bool> &dead){
    vi sz(g.n);
    function<void (int, int)> get_sz = [&](int v, int p){
        sz[v] = 1;
        for(int id : g.adj[v]){
            edge<int> e = g.edges[id];
            int other = e.src ^ e.dest ^ v;
            if(other != p && !dead[other]){
                get_sz(other, v);
                sz[v] += sz[other];
            }
        }
    };
    get_sz(root, -1);
    int n = sz[root];
    function<int (int, int)> dfs = [&](int v, int p){
        for(int id : g.adj[v]){
            edge<int> e = g.edges[id];
            int other = e.src ^ e.dest ^ v;
            if(other != p && !dead[other] && sz[other] > n / 2) return dfs(other, v);
        }
        return v;
    };
    return dfs(root, -1);
}
ll CentroidDecomposition(graph<int> &g){
    ll ans = 0;
    vector<bool> dead(g.n, false);
    function<void (int)> rec = [&](int start){
        int c = OneCentroid(start, g, dead);
        dead[c] = true;
        for(int id : g.adj[c]){
            edge<int> e = g.edges[id];
            int other = e.src ^ e.dest ^ c;
            if(!dead[other]) rec(other);
        };
        // process centroid; 
        vi sz(g.n);
        function<void (int, int)> get_sz = [&](int v, int p){
            sz[v] = 1;
            for(int id : g.adj[v]){
                edge<int> e = g.edges[id];
                int other = e.src ^ e.dest ^ v;
                if(other != p && !dead[other]) {
                    get_sz(other, v);
                    sz[v] += sz[other];
                }
            }
        };
        get_sz(c, -1);
        vi children;
        for(int id : g.adj[c]){
            edge<int> e = g.edges[id];
            int other = e.src ^ e.dest ^ c;
            if(!dead[other]) children.pb(sz[other]);
        }
        ll sum = 0;
        for(auto x : children) sum += x;
        for(auto x : children){
            ans += (ll)x * (sum - (ll)x);
        }
        // end process centoid
        dead[c] = false;
    };
    rec(0);
    return 2*ans;
}
struct AcAutomaton{
    int n, m;
    undigraph<int> g;
	void read_in(){
		cin >> n >> m;
        g = undigraph<int>(n);
        REP(i, m){
            pii e; cin >> e;
            e.ff--; e.ss--;
            g.add_edge(e.ff, e.ss);
        }
	}
	void solve(){
		ll ans = CentroidDecomposition(g);
        cout << ans << endl;
	}
};
    
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: 0 / 5
• Subtask 2: 0 / 11
• Subtask 3: 0 / 8
• Subtask 4: 0 / 10
• Subtask 5: 0 / 13
• Subtask 6: 0 / 15
• Subtask 7: 0 / 20
• Subtask 8: 0 / 8
• Subtask 9: 0 / 10