Submission #1197455

#	Time	Username	Problem	Language	Result	Execution time	Memory
1197455		hackstar	Duathlon (APIO18_duathlon)	C++20	0 / 100	1123 ms	1114112 KiB

count_triplets

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include<bits/stdc++.h>

using namespace std;
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>
using ordered_multiset = tree<T,null_type,less_equal<T>,rb_tree_tag,tree_order_statistics_node_update>;

#pragma GCC optimize("Ofast,O3,unroll-loops")
#pragma GCC target("avx,avx2")

#define int long long
#define ll long long
#define pii pair<int,int>
#define ff first
#define ss second
#define vi vector<int>
#define all(x) (x).begin(),(x).end()
#define rall(x) (x).rbegin(),(x).rend()

template<typename T1,typename T2>
istream& operator>>(istream& cin,pair<T1,T2>& s){
	cin>>s.first>>s.second;
	return cin;
}
template<typename T1,typename T2>
ostream& operator<<(ostream& cout,pair<T1,T2>& s){
	cout<<s.first<<' '<<s.second<<'\n';
	return cout;
}
template<typename T>
istream& operator>>(istream& cin,vector<T>& a){
	for(T& x:a){
		cin>>x;
	}
	return cin;
}
template<typename T>
ostream& operator<<(ostream& cout,vector<T>& a){
	for(T& x:a){
		cout<<x<<' ';
	}
	return cout;
}

const int inf=1e18;

struct LCA {
	int n, LOG;
	vector<vector<pair<int, int>>> g;
	vector<vector<int>> up;
	vector<int> depth;
	vector<int> dist;

	LCA(int _n) : n(_n) {
		LOG = ceil(log2(n)) + 1;
		g.resize(n);
		up.assign(n, vector<int>(LOG, -1));
		depth.resize(n);
		dist.resize(n, 0);
	}

	void add(int u, int v, int w = 1) {
		g[u].push_back({v, w});
		g[v].push_back({u, w});
	}

	void dfs(int v, int p) {
		for (auto &[u, w] : g[v]) {
			if (u == p) continue;
			up[u][0] = v;
			dist[u] = dist[v] + w;
			depth[u] = depth[v] + 1;
			for (int i = 1; i < LOG; i++) {
				if (up[u][i - 1] != -1)
					up[u][i] = up[up[u][i - 1]][i - 1];
			}
			dfs(u, v);
		}
	}

	void init(int root = 0) {
		depth[root] = 0;
		dist[root] = 0;
		dfs(root, -1);
	}

	int get_lca(int u, int v) {
		if (depth[u] < depth[v]) swap(u, v);
		for (int i = LOG - 1; i >= 0; i--) {
			if (depth[u] - (1 << i) >= depth[v])
				u = up[u][i];
		}
		if (u == v) return u;
		for (int i = LOG - 1; i >= 0; i--) {
			if (up[u][i] != up[v][i]) {
				u = up[u][i];
				v = up[v][i];
			}
		}
		return up[u][0];
	}

	int get_distance(int u, int v) {
		int lca = get_lca(u, v);
		return dist[u] + dist[v] - 2 * dist[lca];
	}

	auto get_graph() {
		return g;
	}
};

void solve(){
	int n,m;
	cin>>n>>m;
	LCA lca(n);
	for(int i=0;i<m;i++){
		int u,v;
		cin>>u>>v;
		u--,v--;
		lca.add(u,v);
	}
	lca.init();
	auto dist=[&](int u,int v)->int{
		return lca.get_distance(u,v);
	};
	int ans=0;
	for(int i=0;i<n;i++){
		for(int j=0;j<n;j++){
			if(i==j){
				continue;
			}
			int cur=dist(i,j)-1;
			ans+=max(0ll,cur);
		}
	}
	cout<<ans;
}

signed main(){
	cin.tie(nullptr)->sync_with_stdio(false);
	int t=1;
	#ifdef LOCAL
		freopen("input.txt", "r", stdin);
		freopen("output.txt", "w", stdout);
	#endif
	//cin>>t;
	while(t--){
		solve();
	}
}

• 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