Submission #1072876

#	Time	Username	Problem	Language	Result	Execution time	Memory
1072876		PenguinsAreCute	Building Skyscrapers (CEOI19_skyscrapers)	C++17	54 / 100	250 ms	19652 KiB

skyscrapers

#include <bits/stdc++.h>
using namespace std;
using i2 = pair<int,int>;
using vi = vector<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 bfs(int x, vector<int> &r, vector<int> &c) {
	vis[x]=1;
	priority_queue<vi,vector<vi>,greater<vi>> pq;
	for(pq.push({r[x],c[x],x});pq.size();) {
		int y = pq.top()[2]; pq.pop();
		perm.push_back(y);
		for(auto z: adj[y]) if(!vis[z]) {
			vis[z]=1;
			pq.push({r[z],c[z],z});
		}
	}
}
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{r[i]+dx[j],c[i]+dy[j],0},lamb);
		if(it!=lst+n&&(*it).x==r[i]+dx[j]&&(*it).y==c[i]+dy[j]) adj[i].push_back((*it).i);
	}
	bfs(min_element(all(r))-begin(r),r,c);
	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:44:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   44 | main() {
      | ^~~~

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