#include <bits/stdc++.h>
using namespace std;
typedef pair<int, int> pii;
const int MAXN = 400;
pii points[MAXN];
int n;
pii operator+(pii a, pii b) {
return pii(a.first+b.first, a.second+b.second);
}
pii operator-(pii a, pii b) {
return pii(a.first-b.first, a.second-b.second);
}
int operator*(pii a, pii b) {
return a.first*b.second-a.second*b.first;
}
pii operator*(int a, pii b) {
return pii(a*b.first, a*b.second);
}
class action {
public:
int a, b, c;
action(int a, int b, int c) : a(a), b(b), c(c) {}
};
vector<action> actions;
void make_action(int a, int b, int c) {
actions.push_back(action(a, b, c));
points[c] = points[a]+points[b]-points[c];
}
void reflect(int a, int b, int c) { // reflect triangle about c
make_action(c, b, a);
make_action(c, a, b);
make_action(c, b, a);
}
bool x_good = 0, y_good = 0;
bool good(int x, int y, int z) {
pii a = 2*points[z]-points[x]-points[y];
if (a.first*a.second >= 0) {
if (a.first != 0 && !x_good) {
if (a.first < 0) {
make_action(x, y, z);
}
x_good = 1;
return 1;
}
if (a.second != 0 && !y_good) {
if (a.second < 0) {
make_action(x, y, z);
}
y_good = 1;
return 1;
}
}
return 0;
}
int main() {
ios_base::sync_with_stdio(false); cin.tie(NULL);
cin >> n;
for (int i = 0; i < n; i++) {
cin >> points[i].first >> points[i].second;
}
int a = 0, b = 1, c = -1;
for (int i = 2; i < n; i++) {
if ((points[i]-points[a])*(points[i]-points[b]) != 0) {
c = i;
break;
}
}
if (c == -1) {
cout << "-1\n";
return 0;
}
for (int i = 0; i < 2; i++) {
if (good(c, b, a)) {
swap(a, c);
}
else if (good(c, a, b)) {
swap(b, c);
}
else if (good(a, b, c)) { // do nothing
}
else {
assert(false);
}
for (int j = 0; j < 30; j++) {
reflect(a, b, c);
make_action(a, b, c);
}
}
for (int i = 0; i < n; i++) {
if (i == a || i == b || i == c) continue;
make_action(a, b, i);
}
cout << actions.size() << "\n";
for (int i = 0; i < actions.size(); i++) {
action m = actions[i];
cout << (1+m.a) << " " << (1+m.b) << " " << (1+m.c) << "\n";
}
}
Compilation message
paralelogrami.cpp: In function 'int main()':
paralelogrami.cpp:109:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<action>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
109 | for (int i = 0; i < actions.size(); i++) {
| ~~^~~~~~~~~~~~~~~~
| # |
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 |
340 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 |
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 |
Correct |
0 ms |
212 KB |
Output is correct |
| 3 |
Incorrect |
1 ms |
212 KB |
Output isn't correct |
| 4 |
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 |
1 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 |
1 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 |
- |
