Submission #1064142

#	Time	Username	Problem	Language	Result	Execution time	Memory
1064142		DorostWef	Longest Trip (IOI23_longesttrip)	C++17	70 / 100	30 ms	604 KiB

longesttrip

#include "longesttrip.h"
#include <bits/stdc++.h>

using namespace std;

#define ask are_connected

std::vector<int> longest_trip(int N, int D) {
	int n = N;
	vector <int> A = {0}, B;
	int lst = -1;
	for (int i = 1; i < n; i++) {
		if (B.empty()) {
			lst = 1;
			bool f = ask ({A.back()}, {i});
			if (f)
				A.push_back(i);
			else {
				B.push_back(i);
			}
		} else {
			if (lst == 2 && ask ({A.back()}, {B.back()})) {
				reverse (B.begin(), B.end());
				for (int x : B)
					A.push_back(x);
				B.clear();
				i--;
			} else if (ask ({A.back()}, {i})) {
				A.push_back(i);
			} else {
				B.push_back(i);
			}
			lst = 2;
		}
	}/*
		cout << "A : ";
		for (int x : A)
		cout << x << ' ';
		cout << '\n';
		cout << "B : ";
		for (int y : B)
		cout << y << ' ';
		cout << '\n';*/
	if (B.empty()) {
		assert (A.size() == n);
		return A;
	}
	if (!ask (A, B)) {
		if (A.size() >= B.size()) {
			assert (A.size() >= (n + 1) / 2);
			return A;
		}
		assert (B.size() >= (n + 1) / 2);
		return B;
	}
	if (ask ({A[0]}, {B[0]})) {
		reverse (A.begin(), A.end());
		for (int x : B) {
			A.push_back(x);
		}
		assert (A.size() == n);
		return A;
	} else {
		bool f;
		if (A.size() >= 2) {
			f = ask ({A[0]}, {A.back()});
			if (!f) {
				for (int x : B) {
					A.push_back(x);
				}
				assert (A.size() == n);
				return A;
			}
		} 
		if (B.size() >= 2) {
			f = ask ({B[0]}, {B.back()});
			if (!f) {
				for (int x : A) {
					B.push_back(x);
				}
				assert (B.size() == n);
				return B;
			}
		}
	}
	int l = -1, r = (int)A.size() - 1;
	while (r - l > 1) {
		int mid = (l + r) >> 1;
		vector <int> C;
		for (int i = 0; i <= mid; i++) {
			C.push_back(A[i]);
		}
		if (ask (C, B)) {
			r = mid;
		} else {
			l = mid;
		}
	}
	vector <int> wef = {A[r]};
	int ww1 = r;
	l = -1, r = (int)B.size() - 1;
	while (r - l > 1) {
		int mid = (l + r) >> 1;
		vector <int> C;
		for (int i = 0; i <= mid; i++) {
			C.push_back(B[i]);
		}
		if (ask (C, wef)) {
			r = mid;
		} else {
			l = mid;
		}
	}
	int ww2 = r;
	vector <int> ans;
	for (int i = ww1 + 1; i < (int)A.size(); i++) {
		ans.push_back(A[i]);
	}
	for (int i = 0; i <= ww1; i++) {
		ans.push_back(A[i]);
	}
	for (int i = ww2; i < (int)B.size(); i++) {
		ans.push_back(B[i]);
	}
	for (int i = 0; i < ww2; i++) {
		ans.push_back(B[i]);
	}
	assert (ask ({A[ww1]}, {B[ww2]}));
	if (A.size() != 1) {
		assert (ask ({A[0]}, {A.back()}));
		for (int i = 0; i < (int)A.size() - 1; i++) {
			assert (ask ({A[i]}, {A[i + 1]}));
		}
	}
	if (B.size() != 1) {
		assert (ask ({B[0]}, {B.back()}));
		for (int i = 0; i < (int)B.size() - 1; i++) {
			assert (ask ({B[i]}, {B[i + 1]}));
		}
	}
	assert (ans.size() == n);
	bool f = true;
	for (int i = 0; i < n - 1; i++) {
		f &= (ask ({ans[i]}, {ans[i + 1]}));
	}
	if (!f) {
		if (A.size() >= 2 && B.size() >= 2)
			exit (2);
	}
	return ans;
}

Compilation message (stderr)

In file included from /usr/include/c++/10/cassert:44,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:33,
                 from longesttrip.cpp:2:
longesttrip.cpp: In function 'std::vector<int> longest_trip(int, int)':
longesttrip.cpp:45:20: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   45 |   assert (A.size() == n);
      |           ~~~~~~~~~^~~~
longesttrip.cpp:50:21: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   50 |    assert (A.size() >= (n + 1) / 2);
      |            ~~~~~~~~~^~~~~~~~~~~~~~
longesttrip.cpp:53:20: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   53 |   assert (B.size() >= (n + 1) / 2);
      |           ~~~~~~~~~^~~~~~~~~~~~~~
longesttrip.cpp:61:20: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   61 |   assert (A.size() == n);
      |           ~~~~~~~~~^~~~
longesttrip.cpp:71:22: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   71 |     assert (A.size() == n);
      |             ~~~~~~~~~^~~~
longesttrip.cpp:81:22: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   81 |     assert (B.size() == n);
      |             ~~~~~~~~~^~~~
longesttrip.cpp:141:21: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
  141 |  assert (ans.size() == n);
      |          ~~~~~~~~~~~^~~~

• Subtask 0: 0 / 0
• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 25 / 25
• Subtask 4: 30 / 60