File size: 3,061 Bytes
1fd0050 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 | #include <iostream>
#include <vector>
#include <algorithm>
#include <random>
#include <chrono>
using namespace std;
// Helper function to test adjacency between two nodes.
// Returns true if x and y are adjacent.
// Assumes the current set S is empty before the call, and leaves S empty after.
bool adj(int x, int y) {
cout << "4 " << x << " " << y << " " << x << " " << y << endl;
cout.flush();
int a, b, c, d;
cin >> a >> b >> c >> d;
return b == 1;
}
// Helper function to test adjacency of x to both a and b.
// Returns a pair (adjacent_to_a, adjacent_to_b).
// Assumes S is empty before the call, and leaves S empty after.
pair<bool, bool> adj2(int x, int a, int b) {
cout << "6 " << x << " " << a << " " << a << " " << b << " " << b << " " << x << endl;
cout.flush();
int r[6];
for (int i = 0; i < 6; ++i) cin >> r[i];
return {r[1] == 1, r[3] == 1};
}
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int subtask, n;
cin >> subtask >> n;
// Random generator for shuffling
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
vector<int> chain;
chain.push_back(1); // start with node 1
vector<int> rem;
for (int i = 2; i <= n; ++i) rem.push_back(i);
bool is_cycle = false;
while (!rem.empty()) {
// Shuffle remaining nodes to avoid worst-case order
shuffle(rem.begin(), rem.end(), rng);
bool attached = false;
for (size_t idx = 0; idx < rem.size(); ++idx) {
int x = rem[idx];
if (chain.size() == 1) {
// Only one node in chain
if (adj(x, chain[0])) {
chain.push_back(x);
rem.erase(rem.begin() + idx);
attached = true;
break;
}
} else {
int left = chain.front();
int right = chain.back();
auto [adjL, adjR] = adj2(x, left, right);
if (adjL && adjR) {
// Closing the cycle
chain.push_back(x);
rem.erase(rem.begin() + idx);
is_cycle = true;
attached = true;
break;
} else if (adjL) {
chain.insert(chain.begin(), x);
rem.erase(rem.begin() + idx);
attached = true;
break;
} else if (adjR) {
chain.push_back(x);
rem.erase(rem.begin() + idx);
attached = true;
break;
}
}
}
if (!attached) {
// This should not happen if the chain is maintained correctly
// but in case of error, we break to avoid infinite loop
break;
}
}
// Output the guessed permutation
cout << "-1";
for (int v : chain) cout << " " << v;
cout << endl;
cout.flush();
return 0;
} |