#include <chameleon.h>
#include <iostream>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <cstring>
#include <chrono>
#include <vector>
#include <map>
#include <random>
#include <set>
#include <algorithm>
#include <math.h>
#include <cstdio>
#include <stdio.h>
#include <queue>
#include <bitset>
#include <cstdlib>
#include <deque>
#include <cassert>
#include <stack>
using namespace std;
#define mp make_pair
#define f first
#define se second
#define pb push_back
#define ppb pop_back
#define ll long long
#define ull unsigned long long
#define cntbit(x) __builtin_popcount(x)
#define endl '\n'
#define uset unordered_set
#define umap unordered_map
#define all(x) x.begin(), x.end()
#define pii pair<int, int>
#define ld long double
#define pll pair<long long, long long>
constexpr int Q_MAX = 20'000;
constexpr int N_MAX = 515;
int n, cl[N_MAX << 1];
vector <int> g[N_MAX << 1];
vector <int> s[2];
void dfs(int v) {
for(int to : g[v])
if(!cl[to]) {
cl[to] = 3 - cl[v];
dfs(to);
}
}
inline bool bad(vector <int> x, int r) {
x.pb(r);
return Query(x) != x.size();
}
int same_color[N_MAX << 1];
inline pii gt(int a, int b) {
return mp(min(a, b), max(a, b));
}
set <pii> is;
int loves[N_MAX << 1];
inline void Solve(int N) {
n = N;
for(int i = 1; i <= 2 * n; ++i) {
for(int j = 0; j < 2; ++j)
s[j].clear();
for(int j = 1; j < i; ++j)
cl[j] = 0;
for(int j = 1; j < i; ++j) {
if(!cl[j]) {
cl[j] = 1;
dfs(j);
}
s[cl[j] - 1].pb(j);
}
for(int j = 0; j < 2; ++j) {
vector <int> cur = s[j];
while(bad(cur, i)) {
int l = 0, r = (int)cur.size() - 1, res = -1;
while(l <= r) {
int mid = l + r >> 1;
if(bad(vector <int> (cur.begin() + mid, cur.end()), i))
l = mid + 1, res = mid;
else
r = mid - 1;
}
assert(res != -1);
g[cur[res]].pb(i), g[i].pb(cur[res]);
cur = vector <int> (cur.begin(), cur.begin() + res);
}
}
}
for(int i = 1; i <= 2 * n; ++i) {
assert(g[i].size() == 1 || g[i].size() == 3);
if(g[i].size() == 1)
same_color[i] = g[i][0];
else {
for(int mask = 0; mask < 8; ++mask) {
if(cntbit(mask) != 2)
continue;
vector <int> now = {i};
for(int j = 0; j < 3; ++j)
if(1 << j & mask)
now.pb(g[i][j]);
if(Query(now) == 1) {
for(int j = 0; j < 3; ++j)
if(!(1 << j & mask))
loves[i] = g[i][j];
}
}
}
}
for(int i = 1; i <= 2 * n; ++i) {
if(g[i].size() == 1)
is.insert(gt(i, same_color[i]));
else {
for(int j = 0; j < 3; ++j) {
if(g[i][j] != loves[i] && loves[g[i][j]] != i) {
same_color[g[i][j]] = i;
same_color[i] = g[i][j];
}
}
}
is.insert(gt(same_color[i], i));
}
for(pii e : is)
Answer(e.f, e.se);
}
Compilation message
chameleon.cpp: In function 'bool bad(std::vector<int>, int)':
chameleon.cpp:58:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
return Query(x) != x.size();
~~~~~~~~~^~~~~~~~~~~
chameleon.cpp: In function 'void Solve(int)':
chameleon.cpp:90:18: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
int mid = l + r >> 1;
~~^~~
/tmp/ccf0moUt.o: In function `main':
grader.cpp:(.text.startup+0x15d): undefined reference to `Solve(int)'
collect2: error: ld returned 1 exit status
