BOJ 9703 - Anti-Arithmetic Permutation [C++]

문제

링크

풀이

#include <iostream>
#include <vector>
using namespace std;
 
bool solve(void) {
  int n; cin >> n;
  vector<int> p(n);
  for (int i=0; i<n; i++) cin >> p[i];
 
  for (int i=0; i<n-2; i++) for (int j=i+1; j<n-1; j++) for (int k=j+1; k<n; k++) {
    if (p[j] - p[i] == p[k] - p[j]) return false;
  }
  return true;
}
 
int main(void) {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
 
  int t; cin >> t;
  for (int i=1; i<=t; i++) {
    cout << "Case #" << i << ": " << (solve() ? "YES" : "NO") << "\n";
  }
  return 0;
}