Submission #1300238

#TimeUsernameProblemLanguageResultExecution timeMemory
1300238mduchelloRoadside Advertisements (NOI17_roadsideadverts)C++20
100 / 100
984 ms34052 KiB
#include<bits/stdc++.h>

using namespace std;

//=====================================================================================================================================

#define ll long long
#define ld long double
#define fi first
#define se second
#define pb push_back
#define pll pair<ll, ll>
#define pli pair<ll, int>
#define pil pair<int, ll>
#define pii pair<int, int>
#define BIT(i, mask) ((mask >> (i)) & 1)
#define DAOBIT(i, mask) ((mask ^ (1 << i)))
#define OFFBIT(i, mask) ((mask & ~(1 << (i))))
#define ONBIT(i, mask) ((mask | (1 << (i))))
#define all(x) (x).begin(), (x).end()
#define Unique(v) v.erase(unique(all(v)), v.end());
#define nmax 1000007

//=====================================================================================================================================

const int N = 1e6 + 7;
const ll mod = 1e9 + 6;
const ll MOD = 1e9 + 7;
const ll inf = 1e18;

bool check_sub2 = 1;

int n, q;
vector<pil> adj[N];
int ts[10];
int u, v;
ll w;
ll sum_w;
//=====================================================================================================================================

void fre(){
    freopen("TET.INP", "r", stdin);
    freopen("TET.out", "w", stdout);
}
ll gcd(ll a, ll b){
    return b ? gcd(b, a % b) : a;
}

ll lcm(ll a, ll b){
    return (a / gcd(a, b)) * b;
}

namespace sub2{
    ll d[N];
    void pre_sub2(int u, int p, ll w){
        d[u] = w;
        for(pil e : adj[u]){
            int v = e.fi;
            ll w2 = e.se;
            if(v == p) continue;
            pre_sub2(v, u, w + w2);
        }
    }
    void solve(){
        int root = 0;
        for(int i = 1; i <= n; i++) if(adj[i].size() == 1) root = i;
        pre_sub2(root, 0, 0);
        while(q--){
            for(int i = 1; i <= 5; i++) cin >> ts[i];
            for(int i = 1; i <= 5; i++) ts[i]++;
            ll ans = 0;
            for(int i = 1; i <= 5; i++){
                for(int j = 1; j <= 5; j++){
                    ans = max(ans, d[ts[j]] - d[ts[i]]);
//                    cout << ts[j] << ' ' << ts[i] << ' ' << d[ts[j]] - d[ts[i]] << '\n';
                }
            }
            cout << ans << '\n';
        }
    }
}

namespace sub3{
    int cnt[N];
    ll wtp[N];
    bool f[N];
    void dfs_sub3(int u, int p){
        if(f[u]) cnt[u]++;
        for(pil e : adj[u]){
            int v = e.fi;
            ll w2 = e.se;
            if(v == p) continue;
            dfs_sub3(v, u);
            wtp[v] = w2;
            cnt[u] += cnt[v];
        }
    }
    void solve(){
        while(q--){
            for(int i = 1; i <= 5; i++) cin >> ts[i];
            for(int i = 1; i <= 5; i++) ts[i]++;
            for(int i = 1; i <= 5; i++) f[ts[i]] = 1;
            ll ans = sum_w;
            dfs_sub3(1, 0);
            for(int i = 1; i <= n; i++){
                if(cnt[i] == 0 || cnt[i] == 5) ans -= wtp[i];
                cnt[i] = 0;
            }
            for(int i = 1; i <= 5; i++) f[ts[i]] = 0;
            cout << ans << '\n';
        }
    }
}


struct LCA
{
	int n, root, LG;
	vector<int> h;
	vector<vector<int>> up;
	vector<vector<ll>> me;
	vector<vector<ll>> sum;
	vector<vector<pll>> adj;
	vector<int> tin, tout;
	int timer;

	LCA(int n, int r = 1) : n(n), root(r), adj(n + 1), h(n + 1)
	{
		LG = 1;
		while ((1 << LG) <= n)
			LG++;

		up.assign(n + 1, vector<int>(LG));
		me.assign(n + 1, vector<ll>(LG, 0));
		sum.assign(n + 1, vector<ll>(LG, 0));
		tin.assign(n + 1, 0);
		tout.assign(n + 1, 0);
		timer = 0;
	}

	void add_edge(int u, int v, ll w = 1)
	{
		adj[u].emplace_back(v, w);
		adj[v].emplace_back(u, w);
	}

	void dfs(int u = -1, int p = -1)
	{
		if (u == -1)
			u = root;
		tin[u] = ++timer;
		up[u][0] = (p == -1 ? u : p);
		for (int j = 1; j < LG; ++j)
		{
			up[u][j] = up[up[u][j - 1]][j - 1];
			me[u][j] = max(me[u][j - 1], me[up[u][j - 1]][j - 1]);
			sum[u][j] = sum[u][j - 1] + sum[up[u][j - 1]][j - 1];
		}

		for (auto [v, w] : adj[u])
		{
			if (v == p)
				continue;
			h[v] = h[u] + 1;
			me[v][0] = w;
			sum[v][0] = w;
			dfs(v, u);
		}

		tout[u] = ++timer;
	}

	bool is_ancestor(int u, int v)
	{
		return tin[u] <= tin[v] && tout[u] >= tout[v];
	}

	int ancestor_k(int u, int k)
	{
		for (int j = 0; j < LG; ++j)
			if (k >> j & 1)
				u = up[u][j];
		return u;
	}

	int get_lca(int u, int v)
	{
		if (h[u] < h[v])
			swap(u, v);

		for (int j = LG - 1; j >= 0; --j)
			if (h[u] - (1 << j) >= h[v])
				u = up[u][j];

		if (u == v)
			return u;

		for (int j = LG - 1; j >= 0; --j)
			if (up[u][j] != up[v][j])
			{
				u = up[u][j];
				v = up[v][j];
			}

		return up[u][0];
	}
	ll path_sum(int u, int v)
	{
		ll res = 0;
		if (h[u] < h[v])
			swap(u, v);
		for (int j = LG - 1; j >= 0; --j)
			if (h[u] - (1 << j) >= h[v])
			{
				res += sum[u][j];
				u = up[u][j];
			}

		if (u == v)
			return res;

		for (int j = LG - 1; j >= 0; --j)
			if (up[u][j] != up[v][j])
			{
				res += sum[u][j];
				res += sum[v][j];
				u = up[u][j];
				v = up[v][j];
			}
		res += sum[u][0];
		res += sum[v][0];
		return res;
	}

	int get_dist(int u, int v)
	{
		int l = get_lca(u, v);
		return h[u] + h[v] - h[l] * 2;
	}
};
//=====================================================================================================================================

int main(){
    cin.tie(0)->sync_with_stdio(0);
  //  fre();
    cin >> n;
    LCA t(n);
    for(int i = 1; i < n; i++){
        cin >> u >> v >> w;
        u++;
        v++;
        adj[u].pb({v, w});
        adj[v].pb({u, w});
        t.add_edge(u, v, w);
        sum_w += w;
        check_sub2 &= (adj[u].size() <= 2);
        check_sub2 &= (adj[v].size() <= 2);
    }
    if(n == 5 && q == 1){
        cout << sum_w << '\n';
        return 0;
    }
    cin >> q;
    if(check_sub2){
        sub2 :: solve();
        return 0;
    }
    if(n <= 50000 && q <= 100){
        sub3 :: solve();
        return 0;
    }
    t.dfs(1);
    while(q--){
        vector<int> nodes(5);
		for(int i = 0; i < 5; i++){
			cin >> nodes[i];
			nodes[i]++;
		}
		sort(nodes.begin(), nodes.end(), [&](int u, int v){ return t.tin[u] < t.tin[v]; });
		vector<int> vt = nodes;
		for(int i = 0; i + 1 < nodes.size(); i++){
			int w = t.get_lca(nodes[i], nodes[i + 1]);
			vt.pb(w);
		}
		sort(vt.begin(), vt.end(), [&](int u, int v){ return t.tin[u] < t.tin[v]; });
		Unique(vt);
		ll ans = 0;
		vector<int> st;
		for(int vtx : vt){
			while(!st.empty() && !t.is_ancestor(st.back(), vtx)) st.pop_back();
			if(!st.empty()){
				ans += t.path_sum(st.back(), vtx);
			}
			st.pb(vtx);
		}

		cout << ans << '\n';
    }
    return 0;
}

Compilation message (stderr)

roadsideadverts.cpp: In function 'void fre()':
roadsideadverts.cpp:42:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   42 |     freopen("TET.INP", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
roadsideadverts.cpp:43:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   43 |     freopen("TET.out", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
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