# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
372997 | Kanon | Stations (IOI20_stations) | C++14 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <station.h>
#include <bits/stdc++.h>
using namespace std;
vector<int> label(int n, int k, vector<int> u, vector<int> v) {
vector<vector<int>> g(n);
for(int i = 0; i < n - 1; i++) {
int a = u[i], b = v[i];
g[a].push_back(b);
g[b].push_back(a);
}
vector<int> ret(n, -1);
vector<int> sub(n);
vector<int> par(n);
function<void(int, int)> dfs = [&](int v, int p) {
par[v] = p;
sub[v] = 1;
for(int i : g[v]) {
if(i == p) continue;
dfs(i, v);
sub[v] += sub[i];
}
};
dfs(0, -1);
function<void(int, int, int, bool)> solve = [&](int v, int L, int R, bool head) {
ret[v] = head ? L : R;
int st = L + head;
for(int i : g[v]) {
if(i == par[v]) continue;
solve(i, st, st + sub[i] - 1, !head);
st += sub[i];
}
};
solve(0, 0, n - 1, true);
return ret;
}
int find_next_station(int s, int t, vector<int> c) {
if(c.size() == 1) return c[0];
int n = c.size();
int par = -1;
for(int i : c) if(par == -1 || abs(s - i) > abs(s - par)) par = i;
for(int i = 0; i < n; i++) if(c[i] == par) {
c.erase(c.begin() + i);
break;
}
c.push_back(s);
sort(c.begin(), c.end());
int beg = c[0], fin = c[n - 1];
if(t < beg || t > fin) return par;
if(beg == s) {
return *lower_bound(c.begin(), c.end(), t);
} else {
return *prev(upper_bound(c.begin(), c.end(), t));
}
}