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OI-codes/NFLSOJ/13340/13340.cpp

75 lines
1.6 KiB
C++

// #include <iostream>
#include <fstream>
// using std::cin;
// using std::cout;
std::ifstream cin("stone.in");
std::ofstream cout("stone.out");
const char endl = '\n';
int n;
int main() {
std::ios::sync_with_stdio(false);
cin.tie(nullptr);
cin >> n;
if (n == 1) {
cout << "YES" << endl
<< 1 << ' ' << 1 << endl;
} else if (n % 4 == 0) {
int k = n / 4;
cout << "YES" << endl;
for (int i = 1; i <= k; i++) {
cout << i << ' ' << n - i + 1 << endl;
}
for (int i = k + 1; i <= 2 * k - 1; i++) {
cout << i << ' ' << n - i << endl;
}
cout << 2 * k << ' ' << 1 << endl;
for (int i = 2 * k + 1; i <= 3 * k - 1; i++) {
cout << i << ' ' << n - i + 1 << endl;
}
cout << 3 * k << ' ' << n - k << endl;
for (int i = 3 * k + 1; i <= 4 * k; i++) {
cout << i << ' ' << n - i + 2 << endl;
}
} else if (n % 4 == 1) {
int k = n / 4;
cout << "YES" << endl;
for (int i = 1; i <= k; i++) {
cout << i << ' ' << n - i + 1 << endl;
}
cout << k + 1 << ' ' << k + 2 << endl;
for (int i = k + 2; i <= 2 * k; i++) {
cout << i << ' ' << n - i + 2 << endl;
}
cout << 2 * k + 1 << ' ' << 1 << endl;
for (int i = 2 * k + 2; i <= 3 * k + 1; i++) {
cout << i << ' ' << n - i + 3 << endl;
}
for (int i = 3 * k + 2; i <= 4 * k + 1; i++) {
cout << i << ' ' << n - i + 2 << endl;
}
} else {
cout << "NO" << endl;
}
return 0;
}