Submission #1137938

#	Time	Username	Problem	Language	Result	Execution time	Memory
1137938		SmuggingSpun	Synchronization (JOI13_synchronization)	C++20	0 / 100	49 ms	17988 KiB

synchronization

#include<bits/stdc++.h>
#define taskname "A"
using namespace std;
const int lim = 1e5 + 5;
const int INF = 1e9;
int n, m, q;
pair<int, int>edge[lim];
vector<int>g[lim];
namespace sub1{
	int ans = 0;
	bitset<lim>state;
	map<pair<int, int>, vector<int>>G_edge;
	void dfs(int s, int p = -1, int t = INF){
		ans++;
		for(int& d : g[s]){
			if(d != p){
				pair<int, int>cur = make_pair(min(s, d), max(s, d));
				auto it = lower_bound(G_edge[cur].begin(), G_edge[cur].end(), t);
				if(it != G_edge[cur].begin()){
					dfs(d, s, *prev(it));
				}
			}
		}
	}
	void solve(){
		state.reset();
		for(int t = 0; t < m; t++){
			int x;
			cin >> x;
			if(state.test(x)){
				state.reset(x);
			}
			else{
				state.set(x);
				G_edge[edge[x]].emplace_back(t);
			}
		}		
		int u;
		cin >> u;
		dfs(u);
		cout << ans;
	}
}
namespace sub23{
	void solve(){

	}
}
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;
	for(int i = 1; i < n; i++){
		auto& [u, v] = edge[i];
		cin >> u >> v;
		if(u > v){
			swap(u, v);
		}
		g[u].emplace_back(v);
		g[v].emplace_back(u);
	}
	if(q == 1){
		sub1::solve();
	}
	else{
		sub23::solve();
	}
}

Compilation message (stderr)

synchronization.cpp: In function 'int main()':
synchronization.cpp:52:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   52 |                 freopen(taskname".inp", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 10
• Subtask 2: 0 / 20
• Subtask 3: 0 / 10
• Subtask 4: 0 / 20
• Subtask 5: 0 / 40