#include "highway.h"
#include <stdlib.h>
using namespace std;
typedef vector<int> vi;
const int N = 90000, M = 130000;
int ii[M], jj[M];
int *eh[N], eo[N];
void append(int i, int h) {
int o = eo[i]++;
if (o >= 2 && (o & o - 1) == 0)
eh[i] = (int *) realloc(eh[i], o * 2 * sizeof *eh[i]);
eh[i][o] = h;
}
int dd[N], qu[N], idx[N];
void bfs(int n, int s) {
int i, head, cnt;
for (i = 0; i < n; i++)
dd[i] = n;
head = cnt = 0;
dd[s] = 0, qu[head + cnt++] = s;
while (cnt) {
int d, o;
i = qu[cnt--, head], idx[i] = head++, d = dd[i] + 1;
for (o = eo[i]; o--; ) {
int h = eh[i][o], j = i ^ ii[h] ^ jj[h];
if (dd[j] > d)
dd[j] = d, qu[head + cnt++] = j;
}
}
}
void find_pair(int n, vi ii_, vi jj_, int a, int b) {
int m = ii_.size(), h, i, j, lower, upper;
vi ww(m, 1);
long long d;
for (i = 0; i < n; i++)
eh[i] = (int *) malloc(2 * sizeof *eh[i]);
for (h = 0; h < m; h++) {
i = ii[h] = ii_[h], j = jj[h] = jj_[h];
append(i, h), append(j, h);
}
d = ask(ww);
lower = -1, upper = n;
while (upper - lower > 1) {
i = (lower + upper) / 2;
for (h = 0; h < m; h++)
ww[h] = ii[h] > i && jj[h] > i;
if (ask(ww) < d)
upper = i;
else
lower = i;
}
i = upper, bfs(n, i);
lower = -1, upper = n;
while (upper - lower > 1) {
int h_ = (lower + upper) / 2;
for (h = 0; h < m; h++)
ww[h] = idx[ii[h]] >= h_ || idx[jj[h]] >= h_;
if (ask(ww) > d / b * a)
lower = h_;
else
upper = h_;
}
i = qu[lower], bfs(n, i);
lower = -1, upper = n;
while (upper - lower > 1) {
int h_ = (lower + upper) / 2;
for (h = 0; h < m; h++)
ww[h] = idx[ii[h]] >= h_ || idx[jj[h]] >= h_;
if (ask(ww) > d / b * a)
lower = h_;
else
upper = h_;
}
j = qu[lower];
answer(i, j);
}
