Submission #564512

#	Time	Username	Problem	Language	Result	Execution time	Memory
564512		shrimb	Building Skyscrapers (CEOI19_skyscrapers)	C++17	8 / 100	1502 ms	724 KiB

skyscrapers

#pragma GCC optimize ("Ofast")
#pragma GCC target ("avx,avx2,fma")

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

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;

template<class x>
using ordered_set = tree<x, null_type,less<x>, rb_tree_tag,tree_order_statistics_node_update>;

#define int long long
#define endl '\n'
#define mod 1000000007
//\
#define mod 1686876991

int n, t;
int x[2001], y[2001];
int dx[] = {-1, 1, 0, 0, 1, 1, -1, -1};
int dy[] = {0, 0, 1, -1, 1, -1, 1, -1};
set<pair<int,int>> pts;
map<int,map<int,int>> pts2;
set<pair<int,int>> placed;
bitset<2001> taken;

signed main () {
    cin.tie(0)->sync_with_stdio(0);

    cin >> n >> t;

    for (int i = 0 ; i < n ; i++) {
        cin >> x[i] >> y[i];
        pts.insert({x[i], y[i]});
        pts2[x[i]][y[i]] = i;
    }

    if (n > 1) {
        for (int i = 0 ; i < n ; i++) {
            bool good = 0;
            for (int d = 0 ; d < 8 ; d++) {
                int u = x[i] + dx[d];
                int v = y[i] + dy[d];
                if (pts.count({u, v})) good = 1;
            }
            if (!good) {
                cout << "NO\n";
                return 0;
            }
        }
    }

    cout << "YES\n";
    int cnt = 0;
    while (cnt < n) {
        // cerr << cnt << endl;
        int bx = -1e9-1, by = -1e9-1;
        int id = 0;
        for (int i = 0 ; i < n ; i++) {
            if (taken[i]) continue;
            for (int d = 0 ; d < 8 ; d++) {
                int u = x[i] + dx[d];
                int v = y[i] + dy[d];
                if (cnt == 0 || (pts2[u].count(v) and taken[pts2[u][v]])) {
                    if (u > bx) {
                        bx = u, by = v, id = i;
                    } else if (u == bx and v < by) {
                        bx = u, by = v, id = i;
                    }
                    break;
                }
            }
        }
        taken[id] = 1;
        cout << id + 1 << endl;
        cnt++;
    }
}

Compilation message (stderr)

skyscrapers.cpp:17:1: warning: multi-line comment [-Wcomment]
   17 | //\
      | ^

• 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