#include "longesttrip.h"
using namespace std;
#include <bits/stdc++.h>
#define F(i, l, r) for (int i = (l); i < (r); ++i)
#define A(a) (a).begin(), (a).end()
int edge[300][300];
int parent[300];
int find(int i) {
return i == parent[i] ? i : parent[i] = find(parent[i]);
}
bool query(vector<int> A, vector<int> B) {
// for (auto x: A) cout << x << endl;
// for (auto x: B) cout << x << endl;
if (A.size() == 1 and B.size() == 1) {
if (edge[A[0]][B[0]]) return 1;
}
bool res = are_connected(A, B);
if (res) {
if (A.size() == 1 and B.size() == 1) {
auto x = A[0], y = B[0];
edge[x][y] = edge[y][x] = 1;
parent[find(x)] = find(y);
}
}
// cout << "FUCK " << endl;
return res;
}
vector<int> longest_trip(int N, int D)
{
iota(parent, parent + N, 0ll);
D = 1;
vector<int> hamil;
auto gen = [&]() {
set<int> v;
vector<bool> seen(N+1);
for (auto x: hamil) seen[x] = 1;
F(i, 0, N) if (!seen[i]) v.insert(i);
return v;
};
if (query({0}, {1})) {
hamil = {0, 1};
} else if (query({1}, {2})) {
hamil = {1, 2};
} else {
edge[0][2] = edge[2][0] = 1; parent[0] = 2;
hamil = {0, 2};
}
while (hamil.size() != N) { // this will reach N, with the exception of one case
// cout << "HOW " << endl;
bool is_two = hamil.size() == 2;
bool can_do_any = false;
if (query({hamil[0]}, {hamil.back()})) {
can_do_any = true; // its true that we have a hamiltonian CYCLE, so rotation is valid.
} else {
// Pick any node not in hamil, this must be connected to either the front or the back.
auto i = *gen().begin();
// cout << "HAHA " << endl;
if (query({hamil[0]}, {i})) hamil.insert(hamil.begin(), i);
else {
edge[hamil.back()][i] = edge[i][hamil.back()] = 1;
parent[find(i)] = find(hamil.back());
hamil.push_back(i);
}
continue;
}
// Okay, we want to find *any* connection between hamil and others, if exists already.
auto bad = gen();
bool seen_edge = false;
F(i, 0, hamil.size()) for (auto y: bad) if (edge[hamil[i]][y]) {
// for (auto x: hamil) cout << x << " "; cout << endl;
if (is_two) {
// attach to the correct end
if (i == 0) hamil.insert(hamil.begin(), y);
else hamil.insert(hamil.end(), y);
} else {
hamil.insert(hamil.begin() + i, y);
while (hamil.back() != y) { // really dumb rotate
auto v = hamil.back(); hamil.pop_back(); hamil.insert(hamil.begin(), v);
}
}
seen_edge = true;
// cout << "GOTO END " << endl;
goto end;
}
end: if (seen_edge) continue;
// Okay, now we want to do the "pick one from end, and two disjoint components" strategy.
while (true) {
int state = 0;
for (auto x: bad) for (auto y: bad) if (find(x) != find(y)) {
if (query({x}, {y})) {
state = 1; goto end2; // we found something good
} else { // one MUST be connected to one of the endpoints
state = 2;
if (query({x}, {hamil[0]})) {
hamil.insert(hamil.begin(), x);
} else {
edge[hamil.back()][x] = edge[x][hamil.back()] = 1;
parent[find(hamil.back())] = find(x);
hamil.push_back(x);
}
goto end2;
}
}
end2:
if (state == 1) continue;
if (state == 2) break;
// OTHERWISE, RARE ONCE IN AN ITERATION CASE: WE ASK IF THERE'S ANY CONNECTION ACROSS BOTH COMPS.
// IF NOT, THEN INSTANTLY KNOW TWO K_N COMPS.
if (!query(hamil, vector<int>(A(bad)))) {
if (hamil.size() < bad.size()) {
hamil = vector<int>(A(bad));
}
return hamil;
}
// ELSE, FIND ANY SPANNING EDGE WITH BSEARCH, TAKE IT. BREAK, WE WILL FIND THE SPANNING EDGE AGAIN NEXT LOOP.
vector<int> cur(A(bad));
while (cur.size() > 1) {
vector<int> shit(cur.begin(), cur.begin() + cur.size()/2);
if (query(hamil, shit)) cur = shit;
else cur = vector<int>(cur.begin() + cur.size() / 2, cur.end());
}
int x = cur[0];
cur = hamil;
while (cur.size() > 1) {
vector<int> shit(cur.begin(), cur.begin() + cur.size()/2);
if (query({x}, shit)) cur = shit;
else cur = vector<int>(cur.begin() + cur.size() / 2, cur.end());
}
int y = cur[0];
edge[x][y] = edge[y][x] = 1;
break;
}
// cout << "WHILE TRUING " << endl;
}
return hamil;
}
Compilation message
longesttrip.cpp: In function 'std::vector<int> longest_trip(int, int)':
longesttrip.cpp:61:25: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
61 | while (hamil.size() != N) { // this will reach N, with the exception of one case
| ~~~~~~~~~~~~~^~~~
longesttrip.cpp:5:40: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
5 | #define F(i, l, r) for (int i = (l); i < (r); ++i)
| ^
longesttrip.cpp:87:9: note: in expansion of macro 'F'
87 | F(i, 0, hamil.size()) for (auto y: bad) if (edge[hamil[i]][y]) {
| ^
longesttrip.cpp:64:14: warning: variable 'can_do_any' set but not used [-Wunused-but-set-variable]
64 | bool can_do_any = false;
| ^~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
0 ms |
344 KB |
Incorrect |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
344 KB |
Output is correct |
| 2 |
Correct |
1 ms |
344 KB |
Output is correct |
| 3 |
Correct |
2 ms |
344 KB |
Output is correct |
| 4 |
Correct |
4 ms |
344 KB |
Output is correct |
| 5 |
Correct |
11 ms |
672 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
344 KB |
Output is correct |
| 2 |
Correct |
1 ms |
344 KB |
Output is correct |
| 3 |
Correct |
3 ms |
344 KB |
Output is correct |
| 4 |
Correct |
5 ms |
344 KB |
Output is correct |
| 5 |
Correct |
10 ms |
600 KB |
Output is correct |
| 6 |
Incorrect |
0 ms |
344 KB |
Incorrect |
| 7 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
344 KB |
Output is correct |
| 2 |
Correct |
1 ms |
344 KB |
Output is correct |
| 3 |
Correct |
2 ms |
344 KB |
Output is correct |
| 4 |
Correct |
4 ms |
344 KB |
Output is correct |
| 5 |
Correct |
10 ms |
600 KB |
Output is correct |
| 6 |
Incorrect |
0 ms |
344 KB |
Incorrect |
| 7 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
3 ms |
344 KB |
Output is correct |
| 2 |
Correct |
2 ms |
344 KB |
Output is correct |
| 3 |
Correct |
2 ms |
344 KB |
Output is correct |
| 4 |
Correct |
4 ms |
344 KB |
Output is correct |
| 5 |
Correct |
10 ms |
600 KB |
Output is correct |
| 6 |
Incorrect |
0 ms |
344 KB |
Incorrect |
| 7 |
Halted |
0 ms |
0 KB |
- |
