Submission #1295514

#	Time	Username	Problem	Language	Result	Execution time	Memory
1295514		shidou26	Duathlon (APIO18_duathlon)	C++20	0 / 100	67 ms	28116 KiB

count_triplets

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

#ifdef KURUMI
    #include "algo/debug.h"
#endif

#define endl '\n'
#define fi first
#define se second
#define sz(v) (int)v.size()
#define all(v) v.begin(), v.end()
#define filter(v) v.resize(unique(all(v)) - v.begin())
#define dbg(x) "[" #x << " = " << x << "]"

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
template<typename T1, typename T2> T2 rand(T1 l, T2 r) {
    return uniform_int_distribution<T2>(l, r)(rng);
}
template<typename T1, typename T2> T2 wrand(T1 l, T2 r, int seed) {
    if(seed == 0) return rand(l, r);
    else return (seed > 0 ? max(rand(l, r), wrand(l, r, seed - 1)) : min(rand(l, r), wrand(l, r, seed + 1)));
}

template<typename S, typename T> bool maximize(S &a, T b) {
    if(a < b) {
        a = b;
        return true;
    }else return false;
}
template<typename S, typename T> bool minimize(S &a, T b) {
    if(a > b) {
        a = b;
        return true;
    }else return false;
}

typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, int> pli;
typedef pair<ll, ll> pll;
typedef tuple<int, int, int> tp3;

const int N = 4e5 + 3;

int n, m;
int eu[N], ev[N];
vector<int> adj[N];

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

    for(int i = 1; i <= m; i++) {
        int u, v; cin >> u >> v;
        eu[i] = u;
        ev[i] = v;
        adj[u].push_back(i);
        adj[v].push_back(i);
    }
}

int timer, square;
int num[N], low[N], wgh[N];
vector<int> rsq[N];
stack<int> sta;

void dfs(int u, int p) {
    num[u] = low[u] = ++timer;
    sta.push(u);

    for(int id : adj[u]) if(id != p) {
        int v = eu[id] ^ ev[id] ^ u;

        if(num[v]) minimize(low[u], num[v]);
        else {
            dfs(v, id);
            minimize(low[u], low[v]);

            if(low[v] >= num[u]) {
                square++;
                wgh[square + n] = 0;

                while(int c = sta.top()) {
                    rsq[square + n].push_back(c);
                    rsq[c].push_back(square + n);
//                    cerr << square + n << " " << c << endl;
                    wgh[square + n]++;
                    sta.pop();
                    if(c == v) break;
                }

                rsq[square + n].push_back(u);
                rsq[u].push_back(square + n);
                wgh[square + n]++;
//                cerr << square + n << " " << u << endl;
            }
        }
    }
}

int siz[N];
ll answer = 0;

void work(int u, int p) {
//    cerr << dbg(u) << endl;
    siz[u] = (u <= n);

    for(int v : rsq[u]) if(v != p) {
        work(v, u);
        answer += 2LL * wgh[u] * siz[u] * siz[v];
//        cerr << dbg(wgh[u]) << dbg(siz[u] * siz[v]) << endl;
        siz[u] += siz[v];
    }

    answer += 2LL * wgh[u] * (n - siz[u]) * siz[u];
//    cerr << dbg(wgh[u]) << dbg((n - siz[u]) * siz[u]) << endl;
}

void process() {
    fill(wgh + 1, wgh + 1 + n, -1);
    for(int i = 1; i <= n; i++) {
        if(!num[i]) {
            dfs(i, -1);
            work(i, -1);
        }
    }

    cout << answer << endl;
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    #define task "DATE"
    if(fopen(task".inp", "r")) {
        freopen(task".inp", "r", stdin);
        freopen(task".out", "w", stdout);
    }

    int testcase = 1; // cin >> testcase;
    for(int i = 1; i <= testcase; i++) {
        input();
        process();
    }

    cerr << "Saa, watashtachi no deeto hajimemashou" << endl;
    cerr << "Atarashii kiseki wo koko kara hajimeru shining place nee mou ichido kimi to..." << endl;

    return 0;
}

Compilation message (stderr)

count_triplets.cpp: In function 'int main()':
count_triplets.cpp:138:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  138 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
count_triplets.cpp:139:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  139 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• 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