#include <cstdio>
#include <cassert>
#include <cctype>
#include <vector>
#include <tuple>
#include <algorithm>
#define let const auto
#define rep(name,beg,end) for(auto lim_##name = end,name = beg;name <= lim_##name;name++)
#define per(name,beg,end) for(auto lim_##name = end,name = beg;name >= lim_##name;name--)
#define repn(lim) for(auto REPN_lIM = lim,REPN = 1;REPN <= REPN_lIM;REPN++)
#define debug(...) fprintf(stderr,__VA_ARGS__)
#define trace() debug("line : %d, Function : %s\n",__LINE__,__FUNCTION__)
constexpr int maxn = 433;
std::vector<std::tuple<int,int,int>> ans;
int n;
struct Point{
int x,y;
Point operator - (const Point &t)const{return Point{x - t.x,y - t.y};}
int operator * (const Point &t)const{
return x * t.y - y * t.x;
}
int h()const{
return (x + 10) * 21 + (y + 10);
}
}p[maxn];
Point nxt(const Point a,const Point b,const Point c){
return Point{a.x + b.x - c.x,a.y + b.y - c.y};
}
bool chk(const Point a,const Point b,const Point c){
return !(((b - a) * (c - a) == 0) && ((a - b) * (c - b) == 0) && ((a - c) * (b - c) == 0));
}
void oper(const int a,const int b,const int c){
ans.emplace_back(a,b,c);
assert(ans.size() <= 2500);
p[c] = nxt(p[a],p[b],p[c]);
}
int main(){
// std::freopen("paralelogrami.in","r",stdin);
// std::freopen("paralelogrami.out","w",stdout);
std::scanf("%d",&n);
rep(i,1,n)std::scanf("%d %d",&p[i].x,&p[i].y);
int a = -1,b = -1,c = -1;
rep(i,1,n)
rep(j,i + 1,n)
rep(k,j + 1,n)
if(chk(p[i],p[j],p[k])){
a = i;
b = j;
c = k;
goto ed;
}
ed:
if(a == -1){
std::puts("-1");
return 0;
}
while(true){
if(p[a].x >= 20 && p[b].x >= 20 && p[c].x >= 20 && p[a].y >= 20 && p[b].y >= 20 && p[c].y >= 20)break;
let mix = std::min({p[a].x,p[b].x,p[c].x});
let miy = std::min({p[a].y,p[b].y,p[c].y});
{
let pa = p[a];
let pb = p[b];
let pc = nxt(p[a],p[b],p[c]);
let nmix = std::min({pa.x,pb.x,pc.x});
let nmiy = std::min({pa.y,pb.y,pc.y});
if(nmix >= mix && nmiy >= miy){
oper(a,b,c);
continue;
}
}
{
let pa = p[a];
let pb = nxt(p[a],p[c],p[b]);
let pc = p[c];
let nmix = std::min({pa.x,pb.x,pc.x});
let nmiy = std::min({pa.y,pb.y,pc.y});
if(nmix >= mix && nmiy >= miy){
oper(a,c,b);
continue;
}
}
{
let pa = nxt(p[b],p[c],p[a]);
let pb = p[b];
let pc = p[c];
let nmix = std::min({pa.x,pb.x,pc.x});
let nmiy = std::min({pa.y,pb.y,pc.y});
if(nmix >= mix && nmiy >= miy){
oper(b,c,a);
continue;
}
}
assert(false);
}
// debug("(%d,%d) (%d,%d) (%d,%d)\n",p[a].x,p[a].y,p[b].x,p[b].y,p[c].x,p[c].y);
rep(i,1,n)
if(i != a && i != b && i != c){
if(chk(p[a],p[b],p[i]))oper(a,b,i);
else if(chk(p[b],p[c],p[i]))oper(b,c,i);
else if(chk(p[a],p[c],p[i]))oper(a,c,i);
}
rep(i,1,n)
assert(p[i].x >= 0),
assert(p[i].y >= 0);
std::printf("%d\n",(int)ans.size());
for(let &t : ans)
std::printf("%d %d %d\n",std::get<0>(t),std::get<1>(t),std::get<2>(t));
// std::fclose(stdin);
// std::fclose(stdout);
return 0;
}
Compilation message
paralelogrami.cpp: In function 'int main()':
paralelogrami.cpp:42:12: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
42 | std::scanf("%d",&n);
| ~~~~~~~~~~^~~~~~~~~
paralelogrami.cpp:43:22: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
43 | rep(i,1,n)std::scanf("%d %d",&p[i].x,&p[i].y);
| ~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
1 ms |
468 KB |
Execution killed with signal 6 |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
212 KB |
Output is correct |
| 2 |
Runtime error |
1 ms |
468 KB |
Execution killed with signal 6 |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
212 KB |
Output is correct |
| 2 |
Runtime error |
1 ms |
468 KB |
Execution killed with signal 6 |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
212 KB |
Output is correct |
| 2 |
Runtime error |
1 ms |
468 KB |
Execution killed with signal 6 |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
1 ms |
468 KB |
Execution killed with signal 6 |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
1 ms |
468 KB |
Execution killed with signal 6 |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
1 ms |
468 KB |
Execution killed with signal 6 |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
1 ms |
468 KB |
Execution killed with signal 6 |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
212 KB |
Output is correct |
| 2 |
Runtime error |
1 ms |
468 KB |
Execution killed with signal 6 |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
1 ms |
468 KB |
Execution killed with signal 6 |
| 2 |
Halted |
0 ms |
0 KB |
- |
