#include <bits/stdc++.h>
#include "highway.h"
using namespace std;
#define MOD 1000000007
#define ll long long int
#define vi vector<int>
#define vii vector< vector<int> >
#define PI 3.1415926535897932384626433832795
#define INF 9223372036854775807LL
#define hashA 1257958787
#define hashB 1539500609
vector<vector<pair<int,int> > > graph (91000,vector<pair<int,int> >());
bool excluded[91000];
bool inset[91000];
bool was[91000];
bool hasspec[91000];
int dis[91000];
int siz[91000];
int par[91000];
ll n,spec,dist;
void dfs(int v) {
was[v] = true;
siz[v] = 1;
for(auto ed : graph[v]) {
if(!was[ed.first] && !excluded[ed.first]) {
par[ed.first] = ed.second;
dis[ed.first] = dis[v]+1;
dfs(ed.first);
if(hasspec[ed.first]) {
hasspec[v] = true;
}
siz[v]+= siz[ed.first];
}
}
if(spec == v) {
hasspec[v] = true;
}
}
void putinset(int v) {
was[v] = inset[v] = true;
for(auto ed : graph[v]) {
if(!was[ed.first] && !excluded[ed.first]) {
putinset(ed.first);
}
}
}
int findset() {
memset(was,false,sizeof(was));
memset(inset,false,sizeof(inset));
int sta;
int cnt = 0;
for(int i = 0; i < n; i++) {
if(!excluded[i]) {
// cout << i << " ";
sta = i;
cnt++;
}
}
//cout << endl;
par[sta] = -1;
dfs(sta);
int big = sta;
while(big != -1) {
//cout << sta << " " << big << endl;
sta = big;
big = -1;
for(auto ed : graph[sta]) {
if(siz[ed.first] > cnt/2 && !excluded[ed.first]) {
big = ed.first;
if(!hasspec[ed.first]) {
hasspec[ed.first] = true;
} else {
hasspec[sta] = false;
}
siz[sta] = cnt-siz[ed.first];
siz[ed.first] = cnt;
break;
}
}
}
vector<pair<int,int> > nodes;
for(auto ed : graph[sta]) {
if(!excluded[ed.first]) {
nodes.push_back({siz[ed.first],ed.first});
}
}
sort(nodes.begin(),nodes.end());
int currsiz = 1;
inset[sta] = true;
memset(was,false,sizeof(was));
was[sta] = true;
bool isspec = false;
int did = 0;
for(auto el : nodes) {
// cout << currsiz << " " << cnt/2 << " " << el.first << endl;
if(abs(cnt/2.0-(currsiz+el.first)) < abs(cnt/2.0-currsiz)+0.001) {
currsiz+= el.first;
// cout << "x";
putinset(el.second);
if(hasspec[el.second]) {
isspec = true;
}
did++;
} else {
break;
}
}
int newspec = -1;
if(isspec) {
int cn = 0;
for(int i = 0; i < n; i++) {
if(!excluded[i]) {
inset[i] = !inset[i];
if(inset[i]) {
cn++;
}
}
}
if(cnt-cn > 1) {
inset[sta] = true;
}
} else if(spec == sta) {
if(nodes.size()-did == 1) {
for(int i = 0; i < n; i++) {
if(!excluded[i]) {
inset[i] = !inset[i];
}
}
newspec = nodes[nodes.size()-1].second;
}
}
vector<int> toask(n-1,0);
for(int i = 0; i < n; i++) {
//cout << excluded[i];
if(inset[i] && i != spec) {
if(spec == -1 && i == sta) {
continue;
}
// cout << "a" << i << " ";
for(auto ed : graph[i]) {
toask[ed.second] = 1;
}
}
}
// cout << spec << " " << sta << " " << inset[0] << " " << inset[1] << " " << inset[2] << " " << inset[3] << endl;
ll x = ask(toask);
// cout << cnt;
if(x > dist) {
for(int i = 0; i < n; i++) {
if(!inset[i] && !excluded[i]) {
excluded[i] = true;
cnt--;
}
}
spec = sta;
if(newspec != -1) {
spec = newspec;
}
} else {
for(int i = 0; i < n; i++) {
if(inset[i]) {
excluded[i] = true;
cnt--;
}
}
cnt++;
if(spec == -1) {
spec = sta;
}
excluded[sta] = false;
}
// cout << "asd" << cnt << endl;
return cnt;
}
void find_pair(int N, vector<int> u, vector<int> v, int A, int B) {
n = N;
for(int i = 0; i < n-1; i++) {
graph[u[i]].push_back({v[i],i});
graph[v[i]].push_back({u[i],i});
}
vector<int> toask(n-1,0);
dist = ask(toask);
spec = -1;
int run = 0;
//cout << "a" << endl;
while(findset() > 1) {run++;}
//cout << spec;
memset(was,false,sizeof(was));
memset(excluded,false,sizeof(excluded));
dis[spec] = 0;
dfs(spec);
vector<int> vec;
for(int i = 0; i < n; i++) {
if(dis[i]*A == dist) {
vec.push_back(i);
}
}
while(vec.size() > 1) {
vector<int> vec1;
vector<int> vec2;
for(int i = 0; i < vec.size(); i++) {
if(i*2 < vec.size()) {
vec1.push_back(vec[i]);
} else {
vec2.push_back(vec[i]);
}
}
vector<int> toaskk(n-1,0);
for(int el : vec1) {
toaskk[par[el]] = 1;
}
if(ask(toaskk) == dist) {
swap(vec,vec2);
} else {
swap(vec,vec1);
}
}
answer(spec,vec[0]);
}
Compilation message
highway.cpp: In function 'void find_pair(int, std::vector<int>, std::vector<int>, int, int)':
highway.cpp:207:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i = 0; i < vec.size(); i++) {
~~^~~~~~~~~~~~
highway.cpp:208:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
if(i*2 < vec.size()) {
~~~~^~~~~~~~~~~~
highway.cpp: In function 'int findset()':
highway.cpp:66:5: warning: 'sta' may be used uninitialized in this function [-Wmaybe-uninitialized]
dfs(sta);
~~~^~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
4 ms |
2676 KB |
Output is incorrect: {s, t} is wrong. |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
9 ms |
2680 KB |
Output is incorrect: more than 100 calls to ask. |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
25 ms |
3704 KB |
Output is incorrect: more than 100 calls to ask. |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
10 ms |
2728 KB |
Output is incorrect: more than 100 calls to ask. |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
22 ms |
2972 KB |
Incorrect |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
16 ms |
2944 KB |
Incorrect |
| 2 |
Halted |
0 ms |
0 KB |
- |
