#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
#define f first
#define s second
const int maxn = 1 << 17;
struct line {
pii a, b;
};
int n, k;
pair<pii, int> p[maxn];
pii org[maxn];
int arr[maxn];
vector<line> add[maxn];
vector<line> rem[maxn];
vector<pair<pii, int> > query[maxn];
vector<int> ans;
ll ccw(pii a, pii b, pii c) {
return ll(a.f) * (b.s - c.s) + ll(b.f) * (c.s - a.s) + ll(c.f) * (a.s - b.s);
}
bool comp(pair<pii, int> a, pair<pii, int> b) {
ll c = ccw(pii(0, 0), a.f, b.f);
if(c == 0)
return a.s < b.s;
return c > 0;
}
bool operator==(line x, line y) {
return x.a == y.a && x.b == y.b;
}
bool operator<(line x, line y) {
if(x == y)
return false;
ll sum = ccw(x.a, y.a, x.b) + ccw(x.b, y.a, y.b);
if(!sum) {
if(x.a.s == y.a.s)
return x.a.f < y.a.f;
return x.a.f < y.a.f;
}
return sum > 0;
}
void sweep() {
multiset<line> st;
for(int t = 1; t <= k; t++) {
for(const line &i : add[t]) {
st.insert(i);
}
line f = *st.begin();
sort(query[t].begin(), query[t].end());
for(const pair<pii, int> &i : query[t]) {
if(ccw(f.a, f.b, i.f) == 0) {
ans.push_back(i.s);
}
break;
}
for(const line &i : rem[t]) {
auto it = st.find(i);
st.erase(it);
}
}
}
void add_edge(int i, int j, int x, int y) {
if(i < j) {
add[i].push_back(line{org[x], org[y]});
rem[j].push_back(line{org[x], org[y]});
} else {
add[j].push_back(line{org[y], org[x]});
rem[i].push_back(line{org[y], org[x]});
}
}
void compress() {
sort(p, p + n, comp);
for(int i = 0; i < n; i++) {
if(i == 0 || ccw(pii(0, 0), p[i].f, p[i - 1].f))
k++;
arr[p[i].s] = k;
query[k].push_back(p[i]);
}
}
a
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cin >> n;
for(int i = 0; i < n; i++) {
pii tmp;
cin >> tmp.f >> tmp.s;
p[i].f = tmp;
p[i].s = i;
org[i] = p[i].f;
}
compress();
for(int i = 0; i < n - 1; i++)
add_edge(arr[i], arr[i + 1], i, i + 1);
add_edge(arr[n - 1], arr[0], n - 1, 0);
sweep();
cout << ans.size() << endl;
sort(ans.begin(), ans.end());
for(int i : ans) {
cout << i + 1 << " ";
}
cout << endl;
return 0;
}
Compilation message
circuit.cpp:104:1: error: 'a' does not name a type
a
^
