Submission #1060946

#	Time	Username	Problem	Language	Result	Execution time	Memory
1060946		trMatherz	Duathlon (APIO18_duathlon)	C++17	0 / 100	79 ms	28084 KiB

count_triplets

#include <iostream>
 
// #include <fstream>
// std::ifstream cin ("pop.in");
// std::ofstream cout ("pop.out");
 
// includes
#include <cmath>
#include <set>
#include <map>
#include <queue>
#include <string>
#include <vector>
#include <array>
#include <algorithm>
#include <numeric>
#include <iomanip>
#include <unordered_set>
#include <stack>
#include <ext/pb_ds/assoc_container.hpp>
#include <random>
#include <chrono>
#include <bitset>
#include <complex>
 
// usings
using namespace std;
using namespace __gnu_pbds;
 
// misc
#define ll long long
#define ld long double
#define pb push_back
#define pq priority_queue
#define ub upper_bound
#define lb lower_bound
template <typename T, typename U>
bool emin(T &a, const U &b) { return b < a ? a = b, true : false; }
template <typename T, typename U>
bool emax(T &a, const U &b) { return b > a ? a = b, true : false; }
typedef uint64_t hash_t;
 
// vectors
#define vi vector<int>
#define vvi vector<vi>
#define vvvi vector<vvi>
#define vpii vector<pair<int, int>>
#define vvpii vector<vector<pair<int, int>>>
#define vppipi vector<pair<int, pair<int, int>>>
#define vl vector<ll>
#define vvl vector<vl>
#define vvvl vector<vvl>
#define vpll vector<pair<ll, ll>>
#define vvpll vector<vpll>
#define vb vector<bool>
#define vvb vector<vb>
#define vs vector<string>
#define sz(x) (int)x.size()
#define rz resize
#define all(x) x.begin(), x.end()
#define vc vector<char>
#define vvc vector<vc>
 
// pairs
#define pii pair<int, int>
#define pll pair<ll, ll>
#define mp make_pair
#define f first
#define s second
 
// sets
#define si set<int>
#define sl set<ll>
#define ss set<string>
#define in insert
template <class T>
using iset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
 
// maps
#define mii map<int, int>
#define mll map<ll, ll>

// loops
#define FR(x, z, y) for (int x = z; x < y; x++)
#define FRE(x, z, y) FR(x, z, y + 1)
#define F(x, y) FR(x, 0, y)
#define FE(x, y) F(x, y + 1)
#define A(x, y) for (auto &x : y)




struct BCC { 
    int n; vvi a; vb b; vi v; vvi tre; int bad = -1; 
    void init(int tn) { n = tn, a = vvi(n), b = vb(n, false), v = vi(n); }
    void ad(int x, int y) { a[x].pb(y); a[y].pb(x); }
    void go() {
        vvi c; vi stck, num(n, -1), low(n); 
        function<void(int, int, int &)> dfs = [&](int x, int p, int &t) {
            num[x] = low[x] = t++; 
            stck.pb(x); 
            A(u, a[x]) {
                if(u == p) continue; 
                if(num[u] != -1) emin(low[x], num[u]); 
                else {
                    dfs(u, x, t); 
                    emin(low[x], low[u]); 
                    if(low[u] >= num[x]) {
                        b[x] = (num[x] > 0 || num[u] > 1); c.pb({x}); 
                        for(; c.back().back() != u; stck.pop_back()) c.back().pb(stck.back());
                    }
                }
            }
        };
        int t = 0; 
        dfs(0, -1, t); 
        tre = vvi(1); int cur = 0; 
        F(i, n) if(b[i]) v[i] = cur++, tre.pb({}), bad++; 
        A(u, c) {
            int x = cur++; tre.pb({}); 
            A(p, u) {
                if(!b[p]) v[p] = x; 
                else tre[x].pb(v[p]), tre[v[p]].pb(x); 
            }
        }
    }
};
ll an = 0;
BCC a; vl b; int n, m; vb c;
ll amt = 0; 
void plop(int x, int p){
    amt += b[x]; c[x] = true; 
    A(u, a.tre[x]) if(u != p) plop(u, x); 
}
ll dfs(int x, int p){
    ll low = b[x]; 
    A(u, a.tre[x]) {
        if(u == p) continue; 
        ll cur = dfs(u, x); 
        low += cur;
        if(a.bad < x) an -= b[x] * cur * (cur - 1); 
    }
    if(a.bad < x) an -= b[x] * (amt - low) * (amt - low - 1);
    return low; 
}
int main() {
    cin >> n >> m; 
    a.init(n); b = vl(n * 3, 0); c= vb(n * 3, false); 
    F(i, m){
        int x, y; cin >> x >> y; x--; y--; a.ad(x, y); 
    }
    a.go();
    F(i, n) b[a.v[i]]++; 
    F(i, n){
        amt = 0;
        if(!c[a.v[i]]) {
            plop(a.v[i], -1); 
            an += amt * (amt - 1) * (amt - 2); 
            dfs(a.v[i], -1); 
        }
    }
    cout << an; 
}

• 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