Submission #628520

#	Time	Username	Problem	Language	Result	Execution time	Memory
628520		Sorting	Thousands Islands (IOI22_islands)	C++17	10 / 100	33 ms	5272 KiB

islands

#include "islands.h"

#include <variant>
#include <vector>
#include <algorithm>
#include <cmath>

using namespace std;

std::variant<bool, std::vector<int>> find_journey(
    int n, int m, std::vector<int> u, std::vector<int> v) {
    if(n == 2){
        vector<int> cnt[2]{};
        for(int i = 0; i < u.size();++i){
            cnt[u[i]].push_back(i);
        }
        
        if(cnt[0].size() >= 2 && cnt[1].size() >= 1){
            return vector<int>{cnt[0][0], cnt[1][0], cnt[0][1], cnt[0][0], cnt[1][0], cnt[0][1]};
        }
        return false;
    }
    vector<vector<pair<int, int>>> adj(n);
    for(int i = 0; i < m; ++i){
        adj[u[i]].push_back({v[i], i});
        // adj[v[i]].push_back({u[i], i});
    }
    vector<int> ans;
    ans.push_back(adj[0][0].second);
    int x = adj[0][0].first;
    for(int j = 0; j < adj[x].size(); ++j){
        if(adj[x][j].first == 0){
            ans.push_back(adj[x][j].second);
            break;
        }
    }
    ans.push_back(adj[0][1].second);
    x = adj[0][1].first;
    for(int j = 0; j < adj[x].size(); ++j){
        if(adj[x][j].first == 0){
            ans.push_back(adj[x][j].second);
            break;
        }
    }

    ans.push_back(ans[1]);
    ans.push_back(ans[0]);
    ans.push_back(ans[3]);
    ans.push_back(ans[2]);
    return ans;
}

Compilation message (stderr)

islands.cpp: In function 'std::variant<bool, std::vector<int, std::allocator<int> > > find_journey(int, int, std::vector<int>, std::vector<int>)':
islands.cpp:14:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   14 |         for(int i = 0; i < u.size();++i){
      |                        ~~^~~~~~~~~~
islands.cpp:31:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   31 |     for(int j = 0; j < adj[x].size(); ++j){
      |                    ~~^~~~~~~~~~~~~~~
islands.cpp:39:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   39 |     for(int j = 0; j < adj[x].size(); ++j){
      |                    ~~^~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 0 / 21
• Subtask 4: 0 / 24
• Subtask 5: 0 / 45