| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 25722 | gs14004 | Printed Circuit Board (CEOI12_circuit) | C++11 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <limits.h>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <algorithm>
#include <string>
#include <functional>
#include <vector>
#include <numeric>
#include <deque>
#include <bitset>
#include <iostream>
using namespace std;
typedef long long lint;
typedef long double llf;
typedef pair<int, int> pi;
int n;
pi a[100005];
vector<pi> v;
int gcd(int x, int y){
return y ? gcd(y, x%y) : x;
}
bool ccw(pi a, pi b){
return 1ll * b.first * a.second > 1ll * a.first * b.second;
}
bool ccw2(pi a, pi b, pi c){
return ccw(pi(b.first - a.first, b.second - a.second), pi(c.first - a.first, c.second - a.second));
}
bool same(pi a, pi b){
return 1ll * b.first * a.second == 1ll * a.first * b.second;
}
struct line{
int a, b;
lint c;
};
double crs(line a, line b){
return (1.0 * a.b * b.c - 1.0 * a.c * b.b) / (1.0 * a.a * b.b - 1.0 * a.b * b.a);
}
pi compare(pi p, pi q, int r1, int r2){
if(p.first == -1) return q;
if(q.first == -1) return p;
r1 = max(r1, 0);
r2 = min(r2, (int)v.size() - 1);
line p1 = {a[p.second].second - a[p.first].second, a[p.first].first - a[p.second].first, 0ll};
p1.c = - 1ll * p1.a * a[p.first].first - 1ll * p1.b * a[p.first].second;
line p2 = {a[q.second].second - a[q.first].second, a[q.first].first - a[q.second].first, 0ll};
p2.c = - 1ll * p2.a * a[q.first].first - 1ll * p2.b * a[q.first].second;
line p3 = {v[r1].second + v[r2].second, -v[r1].first - v[r2].first, 0ll};
if(crs(p1, p3) < crs(p2, p3)) return p;
return q;
}
struct seg{
int lim;
pi tree[270000];
int ps[270000], pe[270000];
void init(int n){
fill(tree, tree + 270000, pi(-1, -1));
for(lim = 1; lim <= n; lim <<= 1);
for(int i=0; i<lim; i++){
ps[i + lim] = pe[i + lim] = i;
}
for(int i=lim-1; i; i--){
ps[i] = ps[2*i];
pe[i] = pe[2*i+1];
}
}
void add(int s, int e, pi v){
s += lim;
e += lim;
while(s < e){
if(s%2 == 1){
tree[s] = compare(tree[s], v, ps[s], pe[s] + 1);
s++;
}
if(e%2 == 0){
tree[e] = compare(tree[e], v, ps[e], pe[e] + 1);
e--;
}
s >>= 1;
e >>= 1;
}
if(s == e) tree[s] = compare(tree[s], v, ps[s], pe[s] + 1);
}
pi query(int p){
p += lim;
pi ret = tree[p];
while(p > 1){
p >>= 1;
ret = compare(ret, tree[p], ps[p], pe[p] + 1);
}
return ret;
}
}seg;
pi queries[100005];
int main(){
scanf("%d",&n);
for(int i=0; i<n; i++){
scanf("%d %d",&a[i].first, &a[i].second);
int g = gcd(a[i].first, a[i].second);
v.push_back(pi(a[i].first / g, a[i].second / g));
}
a[n] = a[0];
sort(v.begin(), v.end(), ccw);
v.resize(unique(v.begin(), v.end()) - v.begin());
seg.init(v.size() - 1);
for(int i=0; i<n; i++){
int s = lower_bound(v.begin(), v.end(), a[i], ccw) - v.begin();
int e = lower_bound(v.begin(), v.end(), a[i+1], ccw) - v.begin();
if(s == e) continue;
pi val(i, (i+1)%n);
if(s > e){
swap(s, e);
swap(val.first, val.second);
}
seg.add(s, e-1, val);
}
for(int i=0; i<v.size()-1; i++){
queries[i] = query(i);
}
vector<int> v2;
for(int i=0; i<n; i++){
int p = lower_bound(v.begin(), v.end(), a[i], ccw) - v.begin();
bool bad = 0;
if(p != v.size()-1){
pi t = queries[p];
if(ccw2(a[t.second], a[t.first], a[i])){
bad = 1;
}
}
if(p != 0){
pi t = queries[p-1];
if(ccw2(a[t.second], a[t.first], a[i])){
bad = 1;
}
}
if(!bad) v2.push_back(i+1);
}
printf("%d\n",v2.size());
for(auto &i : v2){
printf("%d ",i);
}
}