#include <bits/stdc++.h>
#include "highway.h"
using namespace std;
#define fi first
#define se second
#define ll long long
#define pb push_back
#define ii pair<int,int>
/*
namespace {
constexpr int MAX_NUM_CALLS = 100;
constexpr long long INF = 1LL << 61;
int N, M, A, B, S, T;
std::vector<int> U, V;
std::vector<std::vector<std::pair<int, int>>> graph;
bool answered, wrong_pair;
int num_calls;
int read_int() {
int x;
if (scanf("%d", &x) != 1) {
fprintf(stderr, "Error while reading input\n");
exit(1);
}
return x;
}
void wrong_answer(const char *MSG) {
printf("Wrong Answer: %s\n", MSG);
exit(0);
}
} // namespace
long long ask(const std::vector<int> &w) {
if (++num_calls > MAX_NUM_CALLS) {
wrong_answer("more than 100 calls to ask");
}
if (w.size() != (size_t)M) {
wrong_answer("w is invalid");
}
for (size_t i = 0; i < w.size(); ++i) {
if (!(w[i] == 0 || w[i] == 1)) {
wrong_answer("w is invalid");
}
}
std::vector<bool> visited(N, false);
std::vector<long long> current_dist(N, INF);
std::queue<int> qa, qb;
qa.push(S);
current_dist[S] = 0;
while (!qa.empty() || !qb.empty()) {
int v;
if (qb.empty() ||
(!qa.empty() && current_dist[qa.front()] <= current_dist[qb.front()])) {
v = qa.front();
qa.pop();
} else {
v = qb.front();
qb.pop();
}
if (visited[v]) {
continue;
}
visited[v] = true;
long long d = current_dist[v];
if (v == T) {
return d;
}
for (auto e : graph[v]) {
int vv = e.first;
int ei = e.second;
if (!visited[vv]) {
if (w[ei] == 0) {
if (current_dist[vv] > d + A) {
current_dist[vv] = d + A;
qa.push(vv);
}
} else {
if (current_dist[vv] > d + B) {
current_dist[vv] = d + B;
qb.push(vv);
}
}
}
}
}
return -1;
}
void answer(int s, int t) {
if (answered) {
wrong_answer("answered not exactly once");
}
if (!((s == S && t == T) || (s == T && t == S))) {
wrong_pair = true;
}
answered = true;
}*/
const int nax=130000;
vector<pair<int,int>> adj[nax];
int dis[nax];
vector<int> on(nax);
long long m,n,init;
vector<bool> vis(nax);
int bfs(int x){
for (int i = 0; i < n; ++i)
{
dis[i]=1e9;
vis[i]=0;
}
queue<int> q;
q.push(x);
dis[x]=0;
vis[x]=1;
while(!q.empty()){
int node=q.front();
q.pop();
if(vis[node]) continue;
vis[x]=true;
for(auto u:adj[node]){
if(dis[u.fi]<=dis[node]+1) continue;
q.push(u.fi);
dis[u.fi]=dis[node]+1;
}
}
vector<pair<int,int>> cur;
for (int i = 0; i < n; ++i)
{
cur.pb({dis[i],i});
}
sort(cur.begin(),cur.end());
int l=0;
int r=n;
while(r-l>1){
int mid=(r+l)/2;
for (int i = 0; i < on.size(); ++i) on[i]=1;
for (int i = on.size(); i >= mid-1; --i)
{
for(auto u:adj[cur[i].se]) on[u.se]=0;
}
if(ask(on)==init) l=mid;
else r=mid;
}
//cout <<" "<<cur[l].se<<endl;
return cur[l].se;
}
void find_pair(int N, std::vector<int> U, std::vector<int> V, int A, int B) {
n=N;
m=U.size();
vector<int> cnt;
on.resize(U.size(),0);
for (int i = 0; i < U.size(); ++i)
{
cnt.pb(0);
}
init=ask(cnt);
for (int i = 0; i < U.size(); ++i)
{
adj[U[i]].pb({V[i],i});
adj[V[i]].pb({U[i],i});
}
int S=bfs(bfs(1));
answer(S,bfs(S));
}
/*
int main() {
#ifndef ONLINE_JUDGE
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#endif
N = read_int();
M = read_int();
A = read_int();
B = read_int();
S = read_int();
T = read_int();
U.resize(M);
V.resize(M);
graph.assign(N, std::vector<std::pair<int, int>>());
for (int i = 0; i < M; ++i) {
U[i] = read_int();
V[i] = read_int();
graph[U[i]].push_back({V[i], i});
graph[V[i]].push_back({U[i], i});
}
answered = false;
wrong_pair = false;
num_calls = 0;
find_pair(N, U, V, A, B);
if (!answered) {
wrong_answer("answered not exactly once");
}
if (wrong_pair) {
wrong_answer("{s, t} is wrong");
}
printf("Accepted: %d\n", num_calls);
return 0;
}
*/
Compilation message
highway.cpp: In function 'int bfs(int)':
highway.cpp:143:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
143 | for (int i = 0; i < on.size(); ++i) on[i]=1;
| ~~^~~~~~~~~~~
highway.cpp: In function 'void find_pair(int, std::vector<int>, std::vector<int>, int, int)':
highway.cpp:159:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
159 | for (int i = 0; i < U.size(); ++i)
| ~~^~~~~~~~~~
highway.cpp:164:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
164 | for (int i = 0; i < U.size(); ++i)
| ~~^~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
4184 KB |
Output is incorrect: {s, t} is wrong. |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
4184 KB |
Output is incorrect: {s, t} is wrong. |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
9 ms |
5048 KB |
Output is incorrect: {s, t} is wrong. |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
4440 KB |
Output is incorrect: {s, t} is wrong. |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
10 ms |
5232 KB |
Output is incorrect: {s, t} is wrong. |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
13 ms |
5208 KB |
Output is incorrect: {s, t} is wrong. |
| 2 |
Halted |
0 ms |
0 KB |
- |
