/* * Solution Template for Pairing Cards * * Australian Informatics Olympiad 2025 * * This file is provided to assist with reading of input and writing of output * for the problem. You may modify this file however you wish, or * you may choose not to use this file at all. */ import java.io.*; class Solution { /* N is the number of cards. */ private static int N; /* D and S are the allowed difference and sum of paired cards. */ private static int D; private static int S; /* * A contains the values on the cards. Note that the array starts from 0, and * so the values are A[0] to A[N-1]. */ private static int A[] = new int[200005]; /* * Read the next token from the input file. * Tokens are separated by whitespace, i.e., spaces, tabs and newlines. * If end-of-file is reached then an empty string is returned. */ private static String readToken(BufferedReader in) throws IOException { StringBuffer ans = new StringBuffer(); int next; /* Skip any initial whitespace. */ next = in.read(); while (next >= 0 && Character.isWhitespace((char)next)) next = in.read(); /* Read the following token. */ while (next >= 0 && ! Character.isWhitespace((char)next)) { ans.append((char)next); next = in.read(); } return ans.toString(); } public static void main(String[] args) throws IOException { /* Open the input and output streams for stdin and stdout. */ BufferedReader input_reader = new BufferedReader(new InputStreamReader( System.in)); BufferedWriter output_writer = new BufferedWriter(new OutputStreamWriter( System.out)); /* Read the values of N, D, S, and the values on the cards. */ N = Integer.parseInt(readToken(input_reader)); D = Integer.parseInt(readToken(input_reader)); S = Integer.parseInt(readToken(input_reader)); for (int i = 0; i < N; i++) { A[i] = Integer.parseInt(readToken(input_reader)); } /* * TODO: This is where you should compute your solution. You should output * YES or NO depending on whether it is possible to divide the cards into * N/2 valid pairs. An example of how to output YES is shown below. */ output_writer.write("YES\n"); /* Close the input_reader and output_writer. */ input_reader.close(); output_writer.close(); } }