Submission #810958

#	Time	Username	Problem	Language	Result	Execution time	Memory
810958		treewave	Building Skyscrapers (CEOI19_skyscrapers)	C++17	8 / 100	134 ms	12920 KiB

skyscrapers

#include <bits/stdc++.h>

using namespace std;

int dx[8] = {0, 0, -1, 1, 1, 1, -1, -1};
int dy[8] = {1, -1, 0, 0, 1, -1, 1, -1};

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    int n, t; cin >> n >> t;
    vector<array<int, 2>> points;
    set<int> points_set;
    map<array<int, 2>, int> pt_to_idx;
    for (int i = 0; i < n; i++){
        int x, y; cin >> x >> y;
        points.push_back({x, y});
        points_set.insert(i);
        pt_to_idx[{x, y}] = i;
    }
    queue<int> bfs;
    bfs.push(pt_to_idx.begin()->second);
    set<array<int, 2>> visited;
    visited.insert({points[bfs.front()][0], points[bfs.front()][1]});
    vector<int> ans;
    while (!bfs.empty()){
        int tp = bfs.front(); bfs.pop();
        ans.push_back(tp);
        for (int d = 0; d < 8; d++){
            array<int, 2> new_pt = {points[tp][0] + dx[d], points[tp][1] + dy[d]};
            if (!visited.count(new_pt)){
                if (pt_to_idx.count(new_pt)){
                    visited.insert(new_pt);
                    bfs.push(pt_to_idx[new_pt]);
                }
            }
        }
    }
    if (ans.size() != n){
        cout << "NO\n";
        return 0;
    }
    cout << "YES\n";
    for (int i = 0; i < n; i++){
        cout << ans[i] + 1 << "\n";
    }
//    if (ans.size() == n){
//        cerr << "hi\n";
//        set<array<int, 2>> curr_cells;
//        for (int i = 0; i < n; i++){
//            array<int, 2> cp = points[ans[i]];
//            assert(!curr_cells.count({cp[0], cp[1]+1}) || !curr_cells.count({cp[0], cp[1]-1}) || !curr_cells.count({cp[0]+1, cp[1]}) || !curr_cells.count({cp[0]-1, cp[1]}));
//            curr_cells.insert(cp);
//        }
//    }
}

Compilation message (stderr)

skyscrapers.cpp: In function 'int main()':
skyscrapers.cpp:40:20: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   40 |     if (ans.size() != n){
      |         ~~~~~~~~~~~^~~~

• Subtask 1: 8 / 8
• Subtask 2: 0 / 14
• Subtask 3: 0 / 12
• Subtask 4: 0 / 17
• Subtask 5: 0 / 20
• Subtask 6: 0 / 10
• Subtask 7: 0 / 19