Submission #1072652

#	Time	Username	Problem	Language	Result	Execution time	Memory
1072652		PenguinsAreCute	Building Skyscrapers (CEOI19_skyscrapers)	C++17	0 / 100	25 ms	6296 KiB

skyscrapers

#include <bits/stdc++.h>
using namespace std;
using i2 = pair<int,int>;
#define fi first
#define se second
#define lb lower_bound
#define ub upper_bound
#define all(v) begin(v),end(v)
#define sz(v) int(v.size())
vector<int> perm;
bitset<150005> vis;
vector<int> adj[150005];
void dfs(int x) {
  perm.push_back(x);
  vis[x]=1;
  for(auto i: adj[x]) if(!vis[i]) dfs(i);
}
struct block {int x, y, i;};
vector<int> build_skyscrapers(int t, vector<int> r, vector<int> c) {
  int n = r.size();
  block lst[n];
  for(int i=0;i<n;i++) lst[i]={r[i],c[i],i};
  auto lamb = [](block a, block b){return i2(a.x,a.y)<i2(b.x,b.y);};
  sort(lst,lst+n,lamb);
  int dx[8]={-1,-1,-1,0,0,1,1,1}, dy[8]={-1,0,1,-1,1,-1,0,1};
  for(int i=0;i<n;i++) for(int j=0;j<8;j++) {
    auto it=lb(lst,lst+n,block{i+dx[j],i+dy[j],0},lamb);
    if(it!=lst+n&&(*it).x==i+dx[j]&&(*it).y==i+dy[j]) adj[i].push_back(it-lst);
  }
  dfs(min_element(all(r))-begin(r));
  if(sz(perm)<n) return {-1};
  return perm;
}

// grader
main() {
  int n, t;
  assert(2==scanf("%d %d",&n,&t));
  vector<int> r(n), c(n);
  for(int i=0;i<n;i++) assert(2==scanf("%d %d",&r[i],&c[i]));
  vector<int> v = build_skyscrapers(t,r,c);
  if(v[0]==-1) printf("NO");
  else {
    printf("YES\n");
    for(auto i: v) printf("%d\n",i+1);
  }
}

Compilation message (stderr)

skyscrapers.cpp:36:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   36 | main() {
      | ^~~~

• Subtask 1: 0 / 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