Submission #404320

#	Time	Username	Problem	Language	Result	Execution time	Memory
404320		AmineTrabelsi	Stations (IOI20_stations)	C++14	10 / 100	1069 ms	656 KiB

stations

#include "stations.h"
#include <bits/stdc++.h>
using namespace std;
const int Mx = 1010;
int timer = 0;
int tin[Mx],tout[Mx];
void dfs(int node,int par,vector<int> &labels,vector<vector<int>> &tr){
    tin[node] = timer++;
    for(auto i:tr[node]){
        if(i != par){
            dfs(i,node,labels,tr);
        }
    }
    tout[node] = timer++;
}
vector<int> label(int n, int k, vector<int> u, vector<int> v) {
    vector<int> labels(n);
    vector<vector<int>> tr(n+1,vector<int>(0));
	for (int i = 0; i < n-1; i++) {
		tr[u[i]].push_back(v[i]);
        tr[v[i]].push_back(u[i]);
	}
    dfs(0,-1,labels,tr);
    for(int i=0;i<n;i++){
        labels[i] = tin[i]+tout[i]*1000;
    }
	return labels;
}
int find_next_station(int s, int t, vector<int> c) {
    int s_tin = s%1000, s_tout = s/1000;
    int t_tin = t%1000, t_tout = t%1000;
    // going from s to t
    // if s,t not in each other subtree return c.back()
    if(s_tin >= t_tin && s_tout <= t_tout){
        return c.back();
    }
    if(t_tin >= s_tin && t_tout <= s_tout){
        for(auto p:c){
            int p_tin = p%1000, p_tout = p/1000;
            if(t_tin >= p_tin && t_tout <= p_tout){
                return p;
            }
        }
    }
    return c.back();
}
// c sorted
// small c deeper in the tree
// big c high in tree
// last c is parent 

• Subtask 1: 0 / 5
• Subtask 2: 0 / 8
• Subtask 3: 0 / 16
• Subtask 4: 10 / 10
• Subtask 5: 0 / 61