Official Analysis (C++)

We'll start by saying that for each $i$ in range $[1, N]$, $a_1 = i$. For all other values of $a_i$, we are given $b_i = a_i + a_{i+1}$ for $[1, N)$, or $a_i = b_{i -1} - a_{i - 1}$ for $(1, N]$. We will then check if these values of $a_i$ produce a valid permutation.

Since $N \leq 1000$, we can simulate this process for every possible starting cow and pick the first valid permutation (since that would be the lexicographical minimum).

Implementation

Copy
import java.io.*;
import java.util.*;

public class Photoshoot {
	public static void main(String[] args) throws IOException {
		Kattio io = new Kattio("photo");

		int N = io.nextInt();
		int[] bessieList = new int[N];
		int[] correctList = new int[N];