Submission #1173346

#	Time	Username	Problem	Language	Result	Execution time	Memory
1173346		Muhammet	철인 이종 경기 (APIO18_duathlon)	C++20	10 / 100	1123 ms	1114112 KiB

count_triplets

#include "bits/stdc++.h"

using namespace std;
 
#define ll long long
#define SZ(s) (int)s.size()

const int N = 1e5 + 5;
const int M = 1e9 + 7;

int n, m, h[N], p[N], sp[N][25], vis[N];

ll ans;

vector <int> v[N], v1;

void dfs(int x, int y) {
    vis[x] = true;
    h[x] = h[y] + 1;
    v1.push_back(x);
    p[x] = y;
    for(auto i : v[x]) {
        if(i == y) continue;
        dfs(i, x);
    }
}

int lca(int x, int y) {
    if(h[x] < h[y]) swap(x, y);
    for(int i = 20; i >= 0; i--) {
        if(h[sp[x][i]] >= h[y]) x = sp[x][i];
    }
    if(x == y) return x;
    for(int i = 20; i >= 0; i--) {
        if(sp[x][i] != sp[y][i]) x = sp[x][i], y = sp[y][i];
    }
    return p[x];
}

int f(int x, int y) {
    return max(0, h[x] + h[y] - 2 * h[lca(x, y)] - 1);
}

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

    cin >> n >> m;
    for(int i = 1; i <= m; i++) {
        int u1, u2;
        cin >> u1 >> u2;
        v[u1].push_back(u2);
        v[u2].push_back(u1);
    }
    for(int i = 1; i <= n; i++) {
        if(vis[i]) continue;
        vis[i] = true;

        v1.clear();
        dfs(i, 0);

        for(auto j : v1) {
            sp[j][0] = p[j];
        }

        for(int j = 1; j <= 20; j++) {
            for(auto i1 : v1) {
                sp[i1][j] = sp[sp[i1][j-1]][j-1];
            }
        }

        for(auto i1 : v1) {
            for(auto i2 : v1) {
                ans += (f(i1, i2));
            }
        }
    }

    cout << ans;

    return 0;
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 11
• Subtask 3: 0 / 8
• Subtask 4: 10 / 10
• Subtask 5: 0 / 13
• Subtask 6: 0 / 15
• Subtask 7: 0 / 20
• Subtask 8: 0 / 8
• Subtask 9: 0 / 10