#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define mp make_pair
#define pb push_back
#define x first
#define y second
#define pii pair<int, int>
#define p3i pair<pii, int>
#define pll pair<ll, ll>
#define p3l pair<pll, ll>
#define vi vector<int>
#define vpii vector<pii>
#define vp3i vector<p3i>
#define vpll vector<pll>
#define vp3l vector<p3l>
#define lseg L, (L+R)/2, N*2+1
#define rseg (L+R)/2+1, R, N*2+2
#define ub upper_bound
#define lb lower_bound
#define pq priority_queue
#define MN 1000000007
#define fox(k, x) for (int k=0; k<x; ++k)
#define fox1(k, x) for (int k=1; k<=x; ++k)
#define foxr(k, x) for (int k=x-1; k>=0; --k)
#define fox1r(k, x) for (int k=x; k>0; --k)
#define ms multiset
#define flood(x) memset(x, 0x3f3f3f3f, sizeof x)
#define drain(x) memset(x, 0, sizeof x)
#define rng() ((rand() << 14)+rand())
#define scan(X) do{while((X=getchar())<'0'); for(X-='0'; '0'<=(_=getchar()); X=(X<<3)+(X<<1)+_-'0');}while(0)
char _;
#define pi 3.14159265358979323846
#include "highway.h"
int n, m, a, b, sz[90005];
ll dis;
vector<pii> v[90005];
bool u[90005], typ;
vector<int> on;
vector<int> out;
bool split = 0;
void dfs0(int N, int P){
sz[N] = 1;
for(auto i:v[N]){
if (i.x == P || u[i.y]) continue;
dfs0(i.x, N);
sz[N]+=sz[i.x];
}
//cout <<"*" << N << ' ' << sz[N] << endl;
}
void dfs2(int N, int P){
for(auto i:v[N]){
if (u[i.y] || i.x == P) continue;
on[i.y] = typ;
dfs2(i.x, N);
}
}
void dfs(int N){
//cout << "?";
dfs0(N, -1);
bool done = 0;
int R = N;
int S = sz[N], P = -1, last;
if (S == 1){
out.pb(N);
return;
}
while(!done){
done = 1;
for(auto i:v[N]){
if (u[i.y] || i.x == P) continue;
if (sz[i.x]*2 >= S){
P = N;
N = i.x;
last = i.y;
done = 0;
break;
}
}
}
if (P == -1){
int hs = 0;
for(auto i:v[N]){
if (u[i.y]) continue;
if (sz[i.x] > hs){
hs = sz[i.x];
P = i.x;
last = i.y;
}
}
}
//cout << "?" << last << endl;
on[last] = 1;
typ = 0;
dfs2(P, N);
typ = 1;
dfs2(N, P);
bool res1 = (ask(on) - dis > 0);
typ = 1;
dfs2(P, N);
typ = 0;
dfs2(N, P);
bool res2 = (ask(on) - dis > 0);
//cout << "*" << N << ' ' << P << ' ' << last << ' ' << res1 << ' ' << res2 << ' ' << split<< endl;
typ = 0;
dfs2(P, N);
typ = 0;
dfs2(N, P);
on[last] = 0;
if (res1 == 0 && res2 == 0 && split == 0){
out.pb(N); out.pb(P);
exit(1);
return;
} else if (res1 == 0 && res2 == 0){
out.pb(R);
return;
}
u[last] = 1;
if (!split){
if (res1 && res2) split = 1;
if (res1){
dfs(N);
}
if (res2){
dfs(P);
}
}
else {
if (res1){
dfs(N);
} else {
dfs(P);
}
}
}
void find_pair(int N,vector<int> U, vector<int> V, int A, int B){
n = N; m = U.size(); a = A; b = B;
on = vector<int>(m, 0);
fox(l, m){
v[U[l]].pb(mp(V[l], l));
v[V[l]].pb(mp(U[l], l));
}
dis = ask(vector<int>(m, 0));
dfs(0);
//if (out.size() > 2) exit(1);
//cout << out.size() << endl;
answer(out[0], out[1]);
}
Compilation message
highway.cpp: In function 'void dfs(int)':
highway.cpp:94:10: warning: 'last' may be used uninitialized in this function [-Wmaybe-uninitialized]
on[last] = 1;
^
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
4 ms |
2424 KB |
Output is incorrect: {s, t} is wrong. |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
5 ms |
2584 KB |
Output is incorrect: {s, t} is wrong. |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
24 ms |
3576 KB |
Output is incorrect: {s, t} is wrong. |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
5 ms |
2508 KB |
Output is incorrect: {s, t} is wrong. |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
360 ms |
262144 KB |
Execution killed with signal 9 (could be triggered by violating memory limits) |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
327 ms |
262144 KB |
Execution killed with signal 9 (could be triggered by violating memory limits) |
| 2 |
Halted |
0 ms |
0 KB |
- |
