#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i=0;i<n;i++)
#define rng(i,c,n) for(int i=c;i<n;i++)
#define per(i,n) for(int i=n-1;i>=0;i--)
#define fi first
#define se second
#define pb push_back
#define sz(a) (int)a.size()
#define vec(...) vector<__VA_ARGS__>
#define _3PGDklf ios::sync_with_stdio(0),cin.tie(0)
typedef long long ll;
using pii=pair<int,int>;
using vi=vector<int>;
void print(){cout<<'\n';}
template<class h,class...t>
void print(const h&v,const t&...u){cout<<v<<' ',print(u...);}
// e
struct P{
int x,y;
P(int _x=0,int _y=0):
x(_x),y(_y){}
P operator+(const P&a)const{return {x+a.x,y+a.y};}
P operator-(const P&a)const{return {x-a.x,y-a.y};}
bool operator<(const P&a)const{
return pii(x,y)<pii(a.x,a.y);
}
};
ll ccw(P a,P b,P c){
return a.x*(b.y-c.y)+b.x*(c.y-a.y)+c.x*(a.y-b.y);
}
struct N
{
P pa,pb,pc;
int i,j,k;
};
signed main(){
_3PGDklf;
int n;
cin>>n;
vec(P) pnts(n);
rep(i,n){
cin>>pnts[i].x>>pnts[i].y;
}
bool pok=1;
rep(i,n){
pok=pok*(pnts[i].x>=0 and pnts[i].y>=0);
}
if(pok){
print(0);
return 0;
}
int si=-1,sj=-1,sk=-1;
for(int i=0;i<n and si==-1;i++){
for(int j=i+1;j<n and si==-1;j++){
for(int k=j+1;k<n and si==-1;k++){
if(ccw(pnts[i],pnts[j],pnts[k])!=0){
si=i,sj=j,sk=k;
}
}
}
}
if(si==-1){
print(-1);
return 0;
}
queue<vec(P)> que;
que.push(vec(P){pnts[si],pnts[sj],pnts[sk]});
std::map<vec(P),N> dp;
dp[vec(P){pnts[si],pnts[sj],pnts[sk]}].i=-1;
dp[vec(P){pnts[si],pnts[sj],pnts[sk]}].j=-1;
dp[vec(P){pnts[si],pnts[sj],pnts[sk]}].k=-1;
auto push=[&](P a,P b,P c,int i,int j,int k,P pa,P pb,P pc){
if(dp.find(vec(P){a,b,c})==dp.end()){
vec(P) now={a,b,c};
dp[now].i=i;
dp[now].j=j;
dp[now].k=k;
dp[now].pa=pa;
dp[now].pb=pb;
dp[now].pc=pc;
que.push(now);
}
};
vec(tuple<int,int,int>) pns;
bool here=0;
while(sz(que)){
auto top=que.front();
que.pop();
P a=top[0];
P b=top[1];
P c=top[2];
if(ccw(a,b,c)==0) continue;
if(min({a.x,a.y,b.x,b.y,c.x,c.y})>10){
// print("lets goo");
pnts[si]=a;
pnts[sj]=b;
pnts[sk]=c;
vec(P) now={a,b,c};
while(1){
if(dp[now].i==-1) break;
pns.pb({dp[now].i,dp[now].j,dp[now].k});
vec(P) nenow(3);
nenow[0]=dp[now].pa;
nenow[1]=dp[now].pb;
nenow[2]=dp[now].pc;
now=nenow;
}
break;
}
if(min({a.x,a.y,b.x,b.y,c.x,c.y})<-20){
continue;
}
// shift a
push(c+b-a,b,c,sj,sk,si,a,b,c);
// shift b
push(a,c+a-b,c,si,sk,sj,a,b,c);
// shift c
push(a,b,a+b-c,si,sj,sk,a,b,c);
}
reverse(pns.begin(), pns.end());
rep(i,n){
if(i==si or i==sj or i==sk) continue;
if(pnts[i].x<0 or pnts[i].y<0){
if(ccw(pnts[si],pnts[sj],pnts[i])!=0){
pns.pb({si,sj,i});
}else{
assert(ccw(pnts[si],pnts[sk],pnts[i])!=0);
pns.pb({si,sk,i});
}
}
}
print(sz(pns));
for(auto [i,j,k]:pns){
print(i+1,j+1,k+1);
}
}
Compilation message
paralelogrami.cpp: In function 'int main()':
paralelogrami.cpp:51:10: warning: '*' in boolean context, suggest '&&' instead [-Wint-in-bool-context]
51 | pok=pok*(pnts[i].x>=0 and pnts[i].y>=0);
| ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
paralelogrami.cpp:90:7: warning: unused variable 'here' [-Wunused-variable]
90 | bool here=0;
| ^~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
3 ms |
596 KB |
Output is correct |
| 2 |
Correct |
1 ms |
212 KB |
Output is correct |
| 3 |
Correct |
2 ms |
468 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
340 KB |
Output is correct |
| 2 |
Correct |
1 ms |
340 KB |
Output is correct |
| 3 |
Correct |
3 ms |
468 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
3 ms |
468 KB |
Output is correct |
| 2 |
Correct |
3 ms |
596 KB |
Output is correct |
| 3 |
Correct |
0 ms |
212 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
340 KB |
Output is correct |
| 2 |
Correct |
1 ms |
340 KB |
Output is correct |
| 3 |
Correct |
0 ms |
212 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
7 ms |
1048 KB |
Output is correct |
| 2 |
Correct |
1 ms |
340 KB |
Output is correct |
| 3 |
Correct |
1 ms |
212 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
8 ms |
1108 KB |
Output is correct |
| 2 |
Correct |
1 ms |
340 KB |
Output is correct |
| 3 |
Correct |
2 ms |
468 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
7 ms |
980 KB |
Output is correct |
| 2 |
Correct |
8 ms |
1116 KB |
Output is correct |
| 3 |
Correct |
1 ms |
212 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
212 KB |
Output is correct |
| 2 |
Correct |
9 ms |
1068 KB |
Output is correct |
| 3 |
Correct |
1 ms |
340 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
340 KB |
Output is correct |
| 2 |
Correct |
10 ms |
1048 KB |
Output is correct |
| 3 |
Correct |
3 ms |
596 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
340 KB |
Output is correct |
| 2 |
Correct |
8 ms |
1108 KB |
Output is correct |
| 3 |
Correct |
1 ms |
340 KB |
Output is correct |
