Submission #1056460

#	Time	Username	Problem	Language	Result	Execution time	Memory
1056460		TheQuantiX	Longest Trip (IOI23_longesttrip)	C++17	85 / 100	9 ms	604 KiB

longesttrip

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

using namespace std;
using ll = long long;

ll n, m, q, k, x, y, a, b, c, d;

vector<int> solve2() {
    deque<int> dq;
    x = -1;
    y = -1;
    if (are_connected({0}, {1})) {
        x = 0;
        y = 1;
    }
    else if (are_connected({0}, {2})) {
        x = 0;
        y = 2;
    }
    else {
        x = 1; 
        y = 2;
    }
    dq.push_back(x);
    dq.push_back(y);
    for (int i = 0; i < n; i++) {
        if (i == x || i == y) {
            continue;
        }
        if (are_connected({dq[0]}, {i})) {
            dq.push_front(i);
        }
        else if (d >= 2 || are_connected({dq[dq.size() - 1]}, {i})) {
            dq.push_back(i);
        }
    }
    vector<int> ans;
    for (auto i : dq) {
        ans.push_back(i);
    }
    return ans;
}

vector<int> longest_trip(int N, int D)
{
    n = N;
    d = D;
    if (D >= 2) {
        return solve2();
    }
    deque<int> dq1, dq2;
    dq1.push_back(0);
    for (int i = 1; i < n; i++) {
        if (are_connected({dq1[dq1.size() - 1]}, {i})) {
            dq1.push_back(i);
        }
        else if (dq2.size() == 0 || are_connected({dq2[dq2.size() - 1]}, {i})) {
            dq2.push_back(i);
        }
        else {
            while (!dq2.empty()) {
                dq1.push_back(dq2[dq2.size() - 1]);
                dq2.pop_back();
            }
            dq2.push_back(i);
        }
    }
    vector<int> ans;
    vector<int> ans1, ans2;
    for (auto i : dq1) {
        ans1.push_back(i);
    }
    for (auto i : dq2) {
        ans2.push_back(i);
    }
    if (ans2.size() == 0 || !are_connected(ans1, ans2)) {
        if (dq1.size() > dq2.size()) {
            for (auto i : dq1) {
                ans.push_back(i);
            }
        }
        else {
            for (auto i : dq2) {
                ans.push_back(i);
            }
        }
        return ans;
    }
    if (are_connected({ans1[0]}, {ans2[0]})) {
        reverse(ans1.begin(), ans1.end());
        for (int i : ans2) {
            ans1.push_back(i);
        }
        return ans1;
    }
    // cout << "DEBUG" << endl;
    if (are_connected({ans1[0]}, {ans2[ans2.size() - 1]})) {
        reverse(ans1.begin(), ans1.end());
        reverse(ans2.begin(), ans2.end());
        for (int i : ans2) {
            ans1.push_back(i);
        }
        return ans1;
    }
    if (are_connected({ans1[ans1.size() - 1]}, {ans2[0]})) {
        for (int i : ans2) {
            ans1.push_back(i);
        }
        return ans1;
    }
    if (are_connected({ans1[ans1.size() - 1]}, {ans2[ans2.size() - 1]})) {
        reverse(ans2.begin(), ans2.end());
        for (int i : ans2) {
            ans1.push_back(i);
        }
        return ans1;
    }
    ll l = 0, r = ans1.size() - 1;
    while (r > l) {
        ll mid = (r + l) / 2;
        vector<int> chk;
        for (int i = l; i <= mid; i++) {
            chk.push_back(ans1[i]);
        }
        if (are_connected(chk, ans2)) {
            r = mid;
        }
        else {
            l = mid + 1;
        }
    }
    ll e = l;
    l = 0;
    r = ans2.size() - 1;
    while (r > l) {
        ll mid = (r + l) / 2;
        vector<int> chk;
        for (int i = l; i <= mid; i++) {
            chk.push_back(ans2[i]);
        }
        if (are_connected({ans1[e]}, chk)) {
            r = mid;
        }
        else {
            l = mid + 1;
        }
    }
    ll f = l;
    for (int i = 0; i < ans1.size(); i++) {
        ans.push_back(ans1[(e + 1 + i) % ans1.size()]);
    }
    for (int i = 0; i < ans2.size(); i++) {
        ans.push_back(ans2[(f + i) % ans2.size()]);
    }
    return ans;
}

Compilation message (stderr)

longesttrip.cpp: In function 'std::vector<int> longest_trip(int, int)':
longesttrip.cpp:150:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  150 |     for (int i = 0; i < ans1.size(); i++) {
      |                     ~~^~~~~~~~~~~~~
longesttrip.cpp:153:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  153 |     for (int i = 0; i < ans2.size(); i++) {
      |                     ~~^~~~~~~~~~~~~

• Subtask 0: 0 / 0
• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 25 / 25
• Subtask 4: 45 / 60