oj.uz

Submission #841801

# Submission time Handle Problem Language Result Execution time Memory
841801 2023-09-02T06:22:57 Z emuyumi Longest Trip (IOI23_longesttrip) C++17
15 / 100
 12 ms 856 KB 
#include "longesttrip.h"

#include <bits/stdc++.h>
using namespace std;
using ll = long long;

vector<int> longest_trip(int N, int D) {

	// check if single component
	// if not, each component is clique, problem is then find largest component

	// otherwise, one component,
	// start with one node and keep trying to extend path by randomly querying
	// if gets stuck, that means past must be a clique, done

	int calls = 0;
	auto my_are_connected = [&](vector<int> a, vector<int> b) {
		calls ++;
		assert(calls <= 32460);
		return are_connected(a, b);
	};

	bool found = 0;
	vector<int> answer;
	using vi = vector<int>;
	auto halves = [&](vector<int> v) -> pair<vi, vi> {
		int m = v.size() / 2;
		return {{v.begin(), v.begin()+m}, {v.begin()+m, v.end()}};
	};
	auto locate = [&](vector<int> src, vector<int> dest) -> int {
		while (src.size() != 1) {
			auto [a, b] = halves(src);
			if (my_are_connected(a, dest)) src = a;
			else src = b;
		}
		return src[0];
	};

	vector<int> path = {0};
	vector<int> left(N-1);
	vector<int> clique;
	iota(left.begin(), left.end(), 1);
	while (left.size()) {
		random_shuffle(left.begin(), left.end());

		int v = path.back();
		if (!clique.empty()) {
			if (my_are_connected(clique, {v})) {
				int b = locate(clique, {v});
				clique.erase(find(clique.begin(), clique.end(), b));
				path.push_back(b);
				for (int x : clique) path.push_back(x);
				clique.clear();
				continue;
			}
		}
		while (!left.empty()) {
			int nxt = left.back(); left.pop_back();
			if (!my_are_connected({nxt}, {v})) {
				clique.push_back(nxt);
			}
			else {
				path.push_back(nxt);
				break;
			}
		}
	}

	if (!clique.empty()) {
		clique = clique;
		if (!my_are_connected(path, clique)) {
			if (path.size() > clique.size()) return path;
			else return clique;
		}
		int a = locate(path, clique);
		int b = locate(clique, {a});

		vector<int> ans = clique;
		ans.erase(find(ans.begin(), ans.end(), b));
		ans.push_back(b);
		int j = find(path.begin(), path.end(), a) - path.begin();
		if (j == 0) {
			for (int x : path) {
				ans.push_back(x);
			}
		}
		else {
			for (int i = j; i >= 0; --i) {
				ans.push_back(path[i]);
			}
			for (int i = path.size()-1; i > j; --i) {
				ans.push_back(path[i]);
			}
		}
		// for (int i = 1; i < ans.size(); ++i) {
		// 	assert(my_are_connected({ans[i]}, {ans[i-1]}));
		// }
		return ans;
	}
	for (int i = 1; i < path.size(); ++i) {
		assert(my_are_connected({path[i]}, {path[i-1]}));
	}
	return path;
}

Compilation message

longesttrip.cpp: In function 'std::vector<int> longest_trip(int, int)':
longesttrip.cpp:100:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  100 |  for (int i = 1; i < path.size(); ++i) {
      |                  ~~^~~~~~~~~~~~~
longesttrip.cpp:23:7: warning: unused variable 'found' [-Wunused-variable]
   23 |  bool found = 0;
      |       ^~~~~

Subtask #0
0.0 / 0.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 2 ms 856 KB Output is correct

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 344 KB Output is correct
2 Correct 11 ms 344 KB Output is correct
3 Correct 9 ms 344 KB Output is correct
4 Correct 10 ms 344 KB Output is correct
5 Correct 10 ms 344 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 344 KB Output is correct
2 Correct 10 ms 344 KB Output is correct
3 Correct 9 ms 344 KB Output is correct
4 Correct 10 ms 344 KB Output is correct
5 Correct 11 ms 600 KB Output is correct
6 Correct 8 ms 344 KB Output is correct
7 Correct 7 ms 344 KB Output is correct
8 Correct 8 ms 600 KB Output is correct
9 Correct 9 ms 344 KB Output is correct
10 Correct 12 ms 344 KB Output is correct
11 Correct 9 ms 344 KB Output is correct
12 Correct 10 ms 600 KB Output is correct
13 Correct 12 ms 344 KB Output is correct

Subtask #3
0.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 340 KB Output is correct
2 Correct 8 ms 344 KB Output is correct
3 Correct 8 ms 404 KB Output is correct
4 Correct 10 ms 344 KB Output is correct
5 Correct 11 ms 344 KB Output is correct
6 Correct 8 ms 344 KB Output is correct
7 Correct 10 ms 344 KB Output is correct
8 Correct 8 ms 600 KB Output is correct
9 Correct 10 ms 344 KB Output is correct
10 Correct 12 ms 344 KB Output is correct
11 Correct 10 ms 344 KB Output is correct
12 Correct 9 ms 596 KB Output is correct
13 Correct 10 ms 344 KB Output is correct
14 Correct 8 ms 344 KB Output is correct
15 Correct 8 ms 344 KB Output is correct
16 Incorrect 1 ms 344 KB Incorrect
17 Halted 0 ms 0 KB -

Subtask #4
0.0 / 60.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 344 KB Output is correct
2 Correct 8 ms 344 KB Output is correct
3 Correct 9 ms 344 KB Output is correct
4 Correct 9 ms 596 KB Output is correct
5 Partially correct 9 ms 344 KB Output is partially correct
6 Correct 8 ms 344 KB Output is correct
7 Correct 9 ms 344 KB Output is correct
8 Correct 9 ms 600 KB Output is correct
9 Correct 8 ms 600 KB Output is correct
10 Partially correct 10 ms 344 KB Output is partially correct
11 Partially correct 11 ms 600 KB Output is partially correct
12 Partially correct 10 ms 344 KB Output is partially correct
13 Partially correct 10 ms 344 KB Output is partially correct
14 Correct 6 ms 344 KB Output is correct
15 Correct 6 ms 344 KB Output is correct
16 Incorrect 1 ms 344 KB Incorrect
17 Halted 0 ms 0 KB -