#include<bits/stdc++.h>
using namespace std;
// #include "meetings.h"
#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")
#include "meetings.h"
#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <set>
#include <utility>
#include <vector>
namespace {
const int MAX_N = 2000;
const int MAX_CALLS = 100000;
void WrongAnswer(int code) {
printf("Wrong Answer [%d]\n", code);
exit(0);
}
int N, num_calls;
std::vector<int> graph[MAX_N];
std::set<std::pair<int, int>> edges, edges_reported;
int weight[MAX_N];
bool Visit(int p, int e, int rt = -1) {
if (p == e) {
++weight[p];
return true;
}
for (int q : graph[p]) {
if (q != rt) {
if (Visit(q, e, p)) {
++weight[p];
return true;
}
}
}
return false;
}
} // namespace
int Query(int u, int v, int w) {
if (!(0 <= u && u <= N - 1 && 0 <= v && v <= N - 1 && 0 <= w && w <= N - 1 &&
u != v && u != w && v != w)) {
WrongAnswer(1);
}
if (++num_calls > MAX_CALLS) {
WrongAnswer(2);
}
std::fill(weight, weight + N, 0);
Visit(u, v);
Visit(u, w);
Visit(v, w);
for (int x = 0; x < N; ++x) {
if (weight[x] == 3) {
return x;
}
}
printf("Error: the input may be invalid\n");
exit(0);
}
void Bridge(int u, int v) {
// printf("%d %d\n", u, v);
if (!(0 <= u && u < v && v <= N - 1)) {
WrongAnswer(3);
}
if (!(edges.count(std::make_pair(u, v)) >= 1)) {
WrongAnswer(4);
}
if (!(edges_reported.count(std::make_pair(u, v)) == 0)) {
WrongAnswer(5);
}
edges_reported.insert(std::make_pair(u, v));
}
int main() {
if (scanf("%d", &N) != 1) {
fprintf(stderr, "Error while reading input\n");
exit(1);
}
for (int i = 0; i < N - 1; ++i) {
int u, v;
if (scanf("%d%d", &u, &v) != 2) {
fprintf(stderr, "Error while reading input\n");
exit(1);
}
graph[u].push_back(v);
graph[v].push_back(u);
edges.insert(std::make_pair(u, v));
}
num_calls = 0;
Solve(N);
if (edges_reported.size() != static_cast<size_t>(N - 1)) {
WrongAnswer(6);
}
printf("Accepted: %d\n", num_calls);
return 0;
}
#define pb push_back
#define sz(a) (a).size()
std::mt19937 rng(std::chrono::steady_clock::now().time_since_epoch().count() ^ (long long) (make_unique<char>().get()));
constexpr int maxn = 2e3+10;
void solve(vector<int>& a) {
shuffle(a.begin(), a.end(), rng);
if(sz(a) <= 1) return;
if(sz(a) == 2) return (void)(Bridge(min(a[0], a[1]), max(a[0], a[1])));
int divide = Query(a[0], a[1], a[2]);
vector<int> head;
if(divide == a[0]) head.pb(a[1]);
else head.pb(a[0]);
vector<vector<int>> grp;
map<int,int> id;
id[head[0]] = 0;
grp.pb({head[0]});
for(int x : a) {
if(x != divide) {
bool ok = 0;
for(int y : head) {
if(x != y) {
if(Query(divide, x, y) != divide)
ok = 1, grp[id[y]].pb(x);
} else ok = 1;
}
if(!ok) id[x] = sz(head), head.pb(x), grp.pb({x});
}
}
for(int y : head) {
int top = y;
for(int x : grp[id[y]])
if(x != top)
top = Query(divide, x, top);
Bridge(min(divide, top), max(divide, top));
solve(grp[id[y]]);
}
}
void Solve(int n) {
vector<int> a;
for(int i = 0; i < n; i++)
a.pb(i);
solve(a);
}
Compilation message
/tmp/ccrmf4ia.o: In function `Query(int, int, int)':
grader.cpp:(.text+0x110): multiple definition of `Query(int, int, int)'
/tmp/ccqlhkRP.o:meetings.cpp:(.text+0x110): first defined here
/tmp/ccrmf4ia.o: In function `Bridge(int, int)':
grader.cpp:(.text+0x240): multiple definition of `Bridge(int, int)'
/tmp/ccqlhkRP.o:meetings.cpp:(.text+0x300): first defined here
/tmp/ccrmf4ia.o: In function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'
/tmp/ccqlhkRP.o:meetings.cpp:(.text.startup+0x0): first defined here
collect2: error: ld returned 1 exit status
