Submission #497810

#	Time	Username	Problem	Language	Result	Execution time	Memory
497810		MilosMilutinovic	Stations (IOI20_stations)	C++14	Compilation error	0 ms	0 KiB

stations

#include <bits/stdc++.h>

using namespace std;

const int N = 1005;
const int L = 10;

int par[N][L], dep[N];
std::vector<int> G[N];

void dfs_init(int u, int p) {
	par[u][0] = p;
	for (int i = 1; i < L; ++i)
		if (par[u][i - 1] != -1)
			par[u][i] = par[par[u][i - 1]][i - 1];
	for (int v : G[u])
		if (v != p)
			dep[v] = dep[u] + 1, dfs_init(v, u);
}

int lca(int u, int v) {
	if (dep[u] < dep[v]) swap(u, v);
	for (int i = L - 1; ~i; --i)
		if (par[u][i] != -1 && dep[par[u][i]] >= dep[v])
			u = par[u][i];
	if (u == v) return u;
	for (int i = L - 1; ~i; --i)
		if (par[u][i] != par[v][i])
			u = par[u][i], v = par[v][i];
	return (u == v ? u : par[u][0]);
}

std::vector<int> label(int n, int k, std::vector<int> u, std::vector<int> v) {
	for (int i = 0; i < n - 1; ++i) {
		G[u[i]].push_back(v[i]);
		G[v[i]].push_back(u[i]);
	}

	dfs_init(0, -1);

	std::vector<int> l(n);
	iota(l.begin(), l.end(), 0);
	return l;
}

int find_next_station(int s, int t, std::vector<int> c) {
	assert(s < n && t < n);
	std::vector<int> path;
	int l = lca(s, t);
	while (s != -1 && dep[s] >= dep[l]) {
		path.push_back(s);
		s = par[s][0];
	}
	while (t != -1 && dep[t] >= dep[l]) {
		path.push_back(t);
		t = par[t][0];
	}
	int node = 0;
	for (int i : path) for (int j : c)
		if (i == j) node = j;
	return node;
}

Compilation message (stderr)

In file included from /usr/include/c++/10/cassert:44,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:33,
                 from stations.cpp:1:
stations.cpp: In function 'int find_next_station(int, int, std::vector<int>)':
stations.cpp:47:13: error: 'n' was not declared in this scope
   47 |  assert(s < n && t < n);
      |             ^