Submission #282014

#	Time	Username	Problem	Language	Result	Execution time	Memory
282014		bigg	Valley (BOI19_valley)	C++14	23 / 100	182 ms	14584 KiB

valley

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll INF = 1e18;
const int MAXN = 1e5 + 10;
int n;
vector<int >grafo[MAXN];
int tin[MAXN], tout[MAXN], altura[MAXN];
int T;
void dfs(int x, int p){
	tin[x] = ++T;
	for(int i = 0; i < grafo[x].size(); i++){
		int viz = grafo[x][i];//, id = grafo[x][i].second.first;
		if(viz == p /*|| id == ip*/) continue;
		altura[viz] = altura[x] + 1;
		//dist[viz] = dist[x] + grafo[x][i].second.second;
		dfs(viz, x);
	}
	tout[x] =T;
}
int s, e, q;
//std::vector<int> shops;
pair<int, int> arestas[MAXN];
bool checkin(int id1, int id2){
	if(tin[id1] <= tin[id2] && tout[id1] >= tin[id2] ) return true;
	return false;
}
int main(){
	scanf("%d %d %d %d", &n, &s, &q, &e);
	for(int i = 1; i < n; i++){
		int u, v;
		ll w;
		scanf("%d %d %lld", &u, &v, &w);
		grafo[u].push_back(v);
		grafo[v].push_back(u);
		arestas[i] = make_pair(u, v);

	}
	for(int i = 0; i < s; i++){
		int k;
		scanf("%d", &k);
		
	}
	dfs(e, 0);
	for(int i = 1; i <= q; i++){

		int id, k;
		scanf("%d %d", &id, &k);
		int u = arestas[id].first, v = arestas[id].second;
		if(altura[u] < altura[v]) swap(u, v);
		if(checkin(u, k)) printf("0\n");
		else printf("escaped\n");
	}

}

Compilation message (stderr)

valley.cpp: In function 'void dfs(int, int)':
valley.cpp:12:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   12 |  for(int i = 0; i < grafo[x].size(); i++){
      |                 ~~^~~~~~~~~~~~~~~~~
valley.cpp: In function 'int main()':
valley.cpp:29:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   29 |  scanf("%d %d %d %d", &n, &s, &q, &e);
      |  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
valley.cpp:33:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   33 |   scanf("%d %d %lld", &u, &v, &w);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
valley.cpp:41:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   41 |   scanf("%d", &k);
      |   ~~~~~^~~~~~~~~~
valley.cpp:48:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   48 |   scanf("%d %d", &id, &k);
      |   ~~~~~^~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 9
• Subtask 2: 0 / 27
• Subtask 3: 23 / 23
• Subtask 4: 0 / 41