Submission #1063116

#	Time	Username	Problem	Language	Result	Execution time	Memory
1063116		fv3	Fountain Parks (IOI21_parks)	C++17	0 / 100	1 ms	348 KiB

parks

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

using namespace std;
vector<vector<int>> adj;
vector<int> visited;

int DFS(int index)
{
    int sz = 1;
    visited[index] = 1;
    for (auto node : adj[index])
    {
        if (visited[node]) continue;
        sz += DFS(node);
    }
    return sz;
}

int construct_roads(vector<int> x, vector<int> y) 
{
    if (x.size() == 1) 
    {
        build({}, {}, {}, {});
        return 1;
    }

    // x[i] = 2
    const int N = x.size();

    vector<pair<int, int>> l, r;
    for (int i = 0; i < N; i++)
    {
        if (x[i] == 2)
            l.push_back({y[i], i});
        else
            r.push_back({y[i], i});
    }
    sort(l.begin(), l.end());
    sort(r.begin(), r.end());

    adj = vector<vector<int>>(N);
    vector<int> U, V, A, B;
    for (int i = 0; i < l.size() - 1; i++)
    {
        if (l[i].first + 2 != l[i+1].first) continue;
        int a = l[i].second;
        int b = l[i+1].second;

        adj[a].push_back(b);
        adj[b].push_back(a);

        U.push_back(a); 
        V.push_back(b);
        A.push_back(1); 
        B.push_back(l[i].first + 1);
    }
    for (int i = 0; i < r.size() - 1; i++)
    {
        if (r[i].first + 2 != r[i+1].first) continue;
        int a = r[i].second;
        int b = r[i+1].second;

        adj[a].push_back(b);
        adj[b].push_back(a);

        U.push_back(a); 
        V.push_back(b);
        A.push_back(5); 
        B.push_back(r[i].first + 1);
    }

    l.insert(l.end(), r.begin(), r.end());
    sort(l.begin(), l.end());    
    for (int i = 0; i < l.size() - 1; i++)
    {
        if (l[i].first != l[i+1].first) continue;
        int a = l[i].second;
        int b = l[i+1].second;

        adj[a].push_back(b);
        adj[b].push_back(a);

        U.push_back(a); 
        V.push_back(b);
        A.push_back(l[i].first + 1); 
        B.push_back(3);
    }

    visited = vector<int>(N);
    int sz = DFS(0);
    if (sz != N) return 0;

    build(U, V, A, B);
    return 1;
}

Compilation message (stderr)

parks.cpp: In function 'int construct_roads(std::vector<int>, std::vector<int>)':
parks.cpp:44:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   44 |     for (int i = 0; i < l.size() - 1; i++)
      |                     ~~^~~~~~~~~~~~~~
parks.cpp:58:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   58 |     for (int i = 0; i < r.size() - 1; i++)
      |                     ~~^~~~~~~~~~~~~~
parks.cpp:75:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   75 |     for (int i = 0; i < l.size() - 1; i++)
      |                     ~~^~~~~~~~~~~~~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 10
• Subtask 3: 0 / 15
• Subtask 4: 0 / 20
• Subtask 5: 0 / 20
• Subtask 6: 0 / 30