#include <cstdio>
#include <cassert>
#include <cctype>
#include <vector>
#include <tuple>
#include <algorithm>
#include <random>
#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};}
Point operator - (const Point &t)const{return Point{x - t.x,y - t.y};}
bool operator == (const Point &t)const{return 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],seq[233];
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]);
}
std::mt19937 eng(123);
int suf[maxn];
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);
rep(i,1,n)suf[i] = i;
std::shuffle(suf + 1,suf + 1 + n,eng);
int perm[] = {-1,-1,-1,-1};
[&perm](){
rep(i,1,n)
rep(j,i + 1,n)
rep(k,j + 1,n)
if(chk(p[suf[i]],p[suf[j]],p[suf[k]])){
perm[1] = suf[i];
perm[2] = suf[j];
perm[3] = suf[k];
return;
}
}();
if(perm[1] == -1){
std::puts("-1");
return 0;
}
let move_vec = [&perm](const int a,const int b,const int c){
oper(perm[b],perm[c],perm[a]);
oper(perm[a],perm[b],perm[c]);
};
let other = [](const int a,const int b){
if(1 != a && 1 != b)return 1;
if(2 != a && 2 != b)return 2;
if(3 != a && 3 != b)return 3;
return -1;
};
int tot = 0,tar = -1,trans[33];
rep(i,1,3)
rep(j,i + 1,3)
seq[++tot] = p[perm[i]] - p[perm[j]],
seq[++tot] = p[perm[j]] - p[perm[i]];
[&trans,&tar,&tot](){
rep(i,1,tot)trans[i] = i;
do{
Point now{0,0};
rep(i,1,tot){
now = now + seq[trans[i]];
if(now.x > 0 && now.y > 0){
// debug("x : %d\n",trans[1]);
// debug("v : (%d,%d)\n",now.x,now.y);
tar = i;
return;
}
}
}while(std::next_permutation(trans + 1,trans + 1 + tot));
}();
assert(tar != -1);
// debug("tar = %d\n",tar);
// debug("(%d,%d)\n",seq[trans[1]].x,seq[trans[1]].y);
while(true){
// debug("(%d,%d) (%d,%d) (%d,%d)\n",p[perm[1]].x,p[perm[1]].y,p[perm[2]].x,p[perm[2]].y,p[perm[3]].x,p[perm[3]].y);
if(p[perm[1]].x >= 20 && p[perm[1]].y >= 20 && p[perm[2]].x >= 20 && p[perm[2]].y >= 20 && p[perm[3]].x >= 20 && p[perm[3]].y >= 20)break;
rep(id,1,tar){
let v = seq[trans[id]];
[&](){
rep(i,1,3)
rep(j,1,3)
if(i != j && (p[perm[j]] - p[perm[i]]) == v){
move_vec(i,j,other(i,j));
return;
}
}();
}
}
let a = perm[1],b = perm[2],c = perm[3];
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:48:12: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
48 | std::scanf("%d",&n);
| ~~~~~~~~~~^~~~~~~~~
paralelogrami.cpp:49:22: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
49 | rep(i,1,n)std::scanf("%d %d",&p[i].x,&p[i].y);
| ~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
212 KB |
Output is correct |
3 |
Correct |
0 ms |
212 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
212 KB |
Output is correct |
3 |
Correct |
0 ms |
212 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
212 KB |
Output is correct |
3 |
Correct |
0 ms |
212 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
224 KB |
Output is correct |
3 |
Incorrect |
0 ms |
212 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
1 ms |
340 KB |
Execution killed with signal 6 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
1 ms |
340 KB |
Execution killed with signal 6 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
1 ms |
340 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 |
340 KB |
Execution killed with signal 6 |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Runtime error |
1 ms |
340 KB |
Execution killed with signal 6 |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
1 ms |
340 KB |
Execution killed with signal 6 |
2 |
Halted |
0 ms |
0 KB |
- |