Submission #846575

#	Time	Username	Problem	Language	Result	Execution time	Memory
846575		math_rabbit_1028	Longest Trip (IOI23_longesttrip)	C++17	15 / 100	823 ms	1828 KiB

longesttrip

#include <bits/stdc++.h>
#include "longesttrip.h"
using namespace std;

vector<int> longest_trip(int N, int D) {
    int n = N; 
    vector<int> adj[256];
    vector<int> res;
    res.clear();
    for (int i = 0; i < n; i++) adj[i].clear();
    for (int i = 0; i < n; i++) {
        for (int j = i + 1; j < n; j++) {
            if (are_connected({i}, {j})) {
                adj[i].push_back(j);
                adj[j].push_back(i);
            }
        }
    }

    int ch[256]; for (int i = 0; i < n; i++) ch[i] = 0;
    vector<int> path, clique;
    path.push_back(0);
    ch[0] = 1;
    while (true) {
        int bef = path.size();
        for (int i = 0; i < adj[path.back()].size(); i++) {
            int v = adj[path.back()][i];
            if (ch[v] == 0) {
                ch[v] = 1;
                path.push_back(v);
                break;
            }
        }
        if (bef == path.size()) break;
    }
    for (int i = 0; i < n; i++) if (ch[i] == 0) clique.push_back(i);

    bool connected = false;
    for (int i = 0; i < path.size(); i++) {
        for (int j = 0; j < adj[path[i]].size(); j++) {
            if (ch[adj[path[i]][j]] == 0) connected = true;
        }
    }
    if (connected) {
        for (int i = 0; i < adj[path[0]].size(); i++) {
            if (ch[adj[path[0]][i]] == 0) {
                int target = adj[path[0]][i];
                res = path;
                reverse(res.begin(), res.end());
                int t = 0;
                for (t = 0; t < clique.size(); t++) if (clique[t] == target) break;
                for (int j = 0; j < clique.size(); j++) res.push_back(clique[j]);
                return res;
            }
        }
        int s = path.size() - 1;
        for (int i = 0; i < adj[path[s]].size(); i++) {
            if (ch[adj[path[s]][i]] == 0) {
                int target = adj[path[s]][i];
                res = path;
                int t = 0;
                for (t = 0; t < clique.size(); t++) if (clique[t] == target) break;
                swap(clique[0], clique[t]);
                for (int j = 0; j < clique.size(); j++) res.push_back(clique[j]);
                return res;
            }
        }
        for (int i = 0; i < clique.size(); i++) {
            for (int j = 0; j < adj[clique[i]].size(); j++) {
                if (ch[adj[clique[i]][j]] == 1) {
                    int target = adj[clique[i]][j];
                    swap(clique[i], clique.back());
                    res = clique;
                    while (path[0] != target) {
                        int front = path[0];
                        path.erase(path.begin());
                        path.push_back(front);
                    }
                    for (int k = 0; k < path.size(); k++) res.push_back(path[k]);
                    return res;
                }
            }
        }
    }
    else {
        if (path.size() > clique.size()) return path;
        return clique;
    }
    return {}; // never reached
}

Compilation message (stderr)

longesttrip.cpp: In function 'std::vector<int> longest_trip(int, int)':
longesttrip.cpp:26:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   26 |         for (int i = 0; i < adj[path.back()].size(); i++) {
      |                         ~~^~~~~~~~~~~~~~~~~~~~~~~~~
longesttrip.cpp:34:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   34 |         if (bef == path.size()) break;
      |             ~~~~^~~~~~~~~~~~~~
longesttrip.cpp:39:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   39 |     for (int i = 0; i < path.size(); i++) {
      |                     ~~^~~~~~~~~~~~~
longesttrip.cpp:40:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   40 |         for (int j = 0; j < adj[path[i]].size(); j++) {
      |                         ~~^~~~~~~~~~~~~~~~~~~~~
longesttrip.cpp:45:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   45 |         for (int i = 0; i < adj[path[0]].size(); i++) {
      |                         ~~^~~~~~~~~~~~~~~~~~~~~
longesttrip.cpp:51:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   51 |                 for (t = 0; t < clique.size(); t++) if (clique[t] == target) break;
      |                             ~~^~~~~~~~~~~~~~~
longesttrip.cpp:52:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   52 |                 for (int j = 0; j < clique.size(); j++) res.push_back(clique[j]);
      |                                 ~~^~~~~~~~~~~~~~~
longesttrip.cpp:57:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   57 |         for (int i = 0; i < adj[path[s]].size(); i++) {
      |                         ~~^~~~~~~~~~~~~~~~~~~~~
longesttrip.cpp:62:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   62 |                 for (t = 0; t < clique.size(); t++) if (clique[t] == target) break;
      |                             ~~^~~~~~~~~~~~~~~
longesttrip.cpp:64:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   64 |                 for (int j = 0; j < clique.size(); j++) res.push_back(clique[j]);
      |                                 ~~^~~~~~~~~~~~~~~
longesttrip.cpp:68:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   68 |         for (int i = 0; i < clique.size(); i++) {
      |                         ~~^~~~~~~~~~~~~~~
longesttrip.cpp:69:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   69 |             for (int j = 0; j < adj[clique[i]].size(); j++) {
      |                             ~~^~~~~~~~~~~~~~~~~~~~~~~
longesttrip.cpp:79:39: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   79 |                     for (int k = 0; k < path.size(); k++) res.push_back(path[k]);
      |                                     ~~^~~~~~~~~~~~~

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