Submission #1116949

#	Time	Username	Problem	Language	Result	Execution time	Memory
1116949		adaawf	Duathlon (APIO18_duathlon)	C++17	100 / 100	100 ms	29616 KiB

count_triplets

#include <iostream>
#include <vector>
#include <map>
using namespace std;
map<pair<int, int>, int> mm;
vector<int> g[100005], gg[200005], v;
int tin[100005], low[100005], z = 0, db[100005], hh;
long long int s[200005], f[200005], kk = 0, n, res = 0;
void dfs(int x, int p) {
    tin[x] = low[x] = ++z;
    v.push_back(x);
    int c = 0;
    for (int w : g[x]) {
        if (w == p) continue;
        if (tin[w] == 0) {
            dfs(w, x);
            low[x] = min(low[x], low[w]);
            if (low[w] >= tin[x]) {
                hh++;
                gg[hh].push_back(x);
                gg[x].push_back(hh);
                while (1) {
                    int h = v.back();
                    gg[h].push_back(hh);
                    gg[hh].push_back(h);
                    v.pop_back();
                    if (h == w) break;
                }
            }
            c++;
        }
        else low[x] = min(low[x], tin[w]);
    }
    if (p == -1 && c >= 2) {

    }
}
void dfs3(int x, int p) {
    db[x] = 1;
    if (x <= n) kk++;
    for (int w : gg[x]) {
        if (w == p) continue;
        dfs3(w, x);
    }
}
void dfs4(int x, int p) {
    s[x] = (x <= n);
    for (int w : gg[x]) {
        if (w == p) continue;
        dfs4(w, x);
        s[x] += s[w];
        if (x > n) res -= s[w] * (s[w] - 1) * (gg[x].size() - 1);
    }
    if (x > n) res -= (kk - s[x]) * (kk - s[x] - 1) * (gg[x].size() - 1);
}
int main() {
    ios::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    long long int m;
    cin >> n >> m;
    for (int i = 1; i <= m; i++) {
        int u, v;
        cin >> u >> v;
        g[u].push_back(v);
        g[v].push_back(u);
    }
    hh = n;
    for (int i = 1; i <= n; i++) {
        if (tin[i] == 0) {
            dfs(i, -1);
        }
    }
    for (int i = 1; i <= n; i++) {
        if (db[i] == 0) {
            kk = 0;
            dfs3(i, -1);
            res += kk * (kk - 1) * (kk - 2);
            dfs4(i, -1);
        }
    }
    cout << res;
}

• Subtask 1: 5 / 5
• Subtask 2: 11 / 11
• Subtask 3: 8 / 8
• Subtask 4: 10 / 10
• Subtask 5: 13 / 13
• Subtask 6: 15 / 15
• Subtask 7: 20 / 20
• Subtask 8: 8 / 8
• Subtask 9: 10 / 10