Submission #1277193

#	Time	Username	Problem	Language	Result	Execution time	Memory
1277193		SmuggingSpun	Tourism (JOI23_tourism)	C++20	100 / 100	699 ms	20204 KiB

tourism

#include<bits/stdc++.h>
#define taskname "C"
using namespace std;
int n, m, q;
namespace sub12{
	void solve(){
		vector<vector<int>>g(n + 1);
		for(int i = 1; i < n; i++){
			int u, v;
			cin >> u >> v;
			g[u].push_back(v);
			g[v].push_back(u);
		}
		vector<int>parent(n + 1), h(n + 1);
		parent[1] = h[1] = 0;
		function<void(int)>dfs;
		dfs = [&] (int s){
			for(int& d : g[s]){
				if(d != parent[s]){
					h[d] = h[parent[d] = s] + 1;
					dfs(d);
				}
			}
		};
		dfs(1);
		vector<int>lca(m), c(m + 1);
		for(int i = 1; i <= m; i++){
			cin >> c[i];
		}
		for(int i = 1; i < m; i++){
			int u = c[i], v = c[i + 1];
			while(u != v){
				if(h[u] < h[v]){
					swap(u, v);
				}
				u = parent[u];
			}
			lca[i] = u;
		}
		vector<int>p(n);
		iota(p.begin(), p.end(), 1);
		sort(p.begin(), p.end(), [&] (int i, int j){
			return h[i] > h[j];
		});
		for(int _ = 0; _ < q; _++){
			int l, r;
			cin >> l >> r;
			vector<int>f(n + 1, 0);
			for(int i = l; i < r; i++){
				f[c[i]]++;
				f[c[i + 1]]++;
				f[lca[i]]--;
				f[parent[lca[i]]]--;
			}
			int ans = 0;
			for(int& s : p){
				for(int& d : g[s]){
					if(d != parent[s]){
						f[s] += f[d];
					}
				}
				if(f[s] > 0){
					ans++;
				}
			}
			cout << max(ans, 1) << "\n";
		}
	}
}
namespace sub3456{
	const int lim = 1e5 + 5;
	int t_hld = 0, c[lim], parent[lim], head[lim], h[lim], cnt[lim], low[lim], bit[lim], ans[lim];
	vector<int>g[lim];
	vector<pair<int, int>>query[lim];
	map<pair<int, int>, int>range;
	void update(int p, int x){
		for(; p < m; p += p & -p){
			bit[p] += x;
		}
	}
	int get(int p){
		int ans = 0;
		for(; p > 0; p -= p & -p){
			ans += bit[p];
		}
		return ans;
	}
	void dfs(int s){
		cnt[s] = 1;
		for(int& d : g[s]){
			if(d != parent[s]){
				h[d] = h[parent[d] = s] + 1;
				dfs(d);
				cnt[s] += cnt[d];
			}
		}
	}
	void hld(int s){
		low[s] = ++t_hld;
		int heavy = -1;
		for(int& d : g[s]){
			if(d != parent[s] && (heavy == -1 || cnt[d] > cnt[heavy])){
				heavy = d;
			}
		}
		if(heavy != -1){
			head[heavy] = head[s];
			hld(heavy);
		}
		for(int& d : g[s]){
			if(d != parent[s] && d != heavy){
				head[d] = d;
				hld(d);
			}
		}
	}
	void work(int l, int r, int i){
		update(i, r - l + 1);
		map<pair<int, int>, int>::iterator it = range.upper_bound(make_pair(l, INT_MAX));
		if(it != range.begin()){
			it--;
		}
		vector<pair<int, int>>sub;
		vector<pair<pair<int, int>, int>>add;
		for(; it != range.end() && (it->first).first <= r; it++){
			int L, R;
			tie(L, R) = it->first;
			if(R >= l){
				sub.push_back(it->first);
				if(L < l){
					add.push_back(make_pair(make_pair(L, l - 1), it->second));
					update(it->second, -(R - l + 1));
				}
				else if(l <= L && R <= r){
					update(it->second, -(R - L + 1));
				}
				else{
					add.push_back(make_pair(make_pair(r + 1, R), it->second));
					update(it->second, -(r - L + 1));
				}
			}
		}
		for(pair<int, int>& it : sub){
			range.erase(it);
		}
		for(pair<pair<int, int>, int>& it : add){
			range[it.first] = it.second;
		}
		range[make_pair(l, r)] = i;
	}
	void solve(){
		for(int i = 1; i < n; i++){
			int u, v;
			cin >> u >> v;
			g[u].push_back(v);
			g[v].push_back(u);
		}
		for(int i = 1; i <= m; i++){
			cin >> c[i];
		}
		for(int i = 0; i < q; i++){
			int l, r;
			cin >> l >> r;
			query[l].push_back(make_pair(r, i));
		}
		memset(bit, parent[1] = h[1] = 0, sizeof(bit));
		dfs(1);
		hld(head[1] = 1);
		memset(ans, 0, sizeof(ans));
		for(int i = m - 1; i > 0; i--){
			int u = c[i], v = c[i + 1];
			while(head[u] != head[v]){
				if(h[head[u]] < h[head[v]]){
					swap(u, v);
				}
				work(low[head[u]], low[u], i);
				u = parent[head[u]];
			}
			if(low[u] > low[v]){
				swap(u, v);
			}
			work(low[u], low[v], i);
			for(pair<int, int>& it : query[i]){
				ans[it.second] = get(it.first - 1);
			}
		}
		for(int i = 0; i < q; i++){
			cout << max(ans[i], 1) << "\n";
		}
	}
}
int main(){
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	if(fopen(taskname".inp", "r")){
		freopen(taskname".inp", "r", stdin);
	}
	cin >> n >> m >> q;
	if(max({n, m, q}) <= 2000){
		sub12::solve();
	}
	else{
		sub3456::solve();
	}
}

Compilation message (stderr)

tourism.cpp: In function 'int main()':
tourism.cpp:195:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  195 |                 freopen(taskname".inp", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 7 / 7
• Subtask 4: 18 / 18
• Subtask 5: 24 / 24
• Subtask 6: 41 / 41