/* In July 2018 I was on summer camp for children (I was 16 years old). We were divided into teams and these teams were competing against each other in competitions. We completly lost one of these competitions, event through I found the best way to complete the riddle. It was simply too hard to explain the tactic to 13 other children aged 8-15. So I decided to make program that would work as my teammates and see how fast the riddle could have been completed. There were 30 cards with numbers 1 to 30 placed 20 meters away from our base (in 5*6 table). The cards were placed with numbers down, so we couldn't see them. The goal was to collect all the cards, but we could only take the one we are looking for (e. g. we had cards 1, 2, and 3, so we could brought back only card with number 4 on it). In case we found wrong number, we had to left the car there, but we could remember it's position. We were running there and back one after another and we had to keep the order in which we ran the first round. There were 14 people in my team in total and each of us could remember 2-3 cards and their positions. Here in Sololearn my program wouldn't execute in time limit, so I had to make only 15 cards in 3*5 table and 10 players, able to remember 2 cards. I recommend you to download my code into your device and try to change the values. You can also uncomment code in randomize() function in class Program to make cards random and get different result each time. Values to change: Line 49 - size of the memory array - amount of cards each player can remember. Lines 55, 61, 68 - number in the condition of this for loops has to be same as the number on line 49. Line 80 - total amount of players. Line 82 - size of the table the cards are placed in. Lines 96, 106, 162 - same value as the first size on line 82 Line 97, 105, 163 - same value as the second size on line 82 Line 127 - total amount of cards - must be equal to value on line 96 multiplyed by value on line 97 Code was made by Jan Štěch. */ import java.util.ArrayList; class Position { public int x; public int y; public Position(int a, int b){ this.x = a; this.y = b; } } class Card { public int value; public Position position; public Card(int num, int x, int y) { this.value = num; this.position = new Position(x, y); } } class Player { public int id; public Card[] memory = new Card[2]; public Player(int num) { this.id = num; for(int i = 0; i < 2; i++) { this.memory[i] = null; } } public Position getCard(int num) { for(int i = 0; i < 2; i++) { if (this.memory[i].value == num) {return this.memory[i].position;} } return null; } public boolean rememberCard(Card c) { for(int i = 0; i < 2; i++) { if(this.memory[i] == null) { this.memory[i] = c; return true; } } return false; } } public class Program { private static final int totalPlayers = 10; private static Card[][] cards = new Card[3][5]; public static void randomize() { /* int x,y; for(int i = 15; i > 0; i--){ x = (int)(Math.random() * 3); y = (int)(Math.random() * 5); if (cards[x][y] == null){cards[x][y] = new Card(i, x, y);} else {i++; continue;} } */ //I need to place cards in simple order, because otherwise my program wouldn't execute in time limit. If you download my code to your computer, you can use commented function above instead. int i = 1; for(int x = 0; x < 3; x++){ for(int y = 0; y < 5; y++, i++){ cards[x][y]=new Card(i, x, y); } } System.out.println("[SETUP]-- Cards has been randomized."); } public static void print(){ for(int i=0; i<5; i++){ for(int j=0; j<3; j++){ System.out.print(cards[j][i].value); System.out.print(" "); } System.out.println(); } } public static void main(String[] args) { randomize(); print(); ArrayList players = new ArrayList(); int maxCard = 0, runs = 0, current = -1, i = 0, x = 0, y = 0; boolean p = false; for(i = 0; i < totalPlayers; i++) { players.add(new Player(i)); } System.out.println("[SETUP]-- " + totalPlayers + " players have been added."); while(maxCard < 15) { current++; if(current == totalPlayers){ current = 0;} System.out.println("[SEARCH]- Looking for card with number " + (maxCard + 1)); for(i = 0; i < totalPlayers; i++) { try{ if (players.get(i).getCard(maxCard + 1) != null) { System.out.println("[FOUND]-- Player " + (i + 1) + " knows position of the card: [" + players.get(i).getCard(maxCard + 1).x + ";" + players.get(i).getCard(maxCard + 1).y + "] and player " + (current + 1) + " brought it."); maxCard++; runs++; p = true; break; } }catch(Exception e){} } if (p == true){p = false; continue;} System.out.println("[UNKNOWN] No player knows position of card with value " + (maxCard + 1) + ". Remembering card on [" + x + ";" + y + "]."); while (!(players.get(current).rememberCard(cards[x][y]))){ System.out.println("[FAIL]--- Player " + (current + 1) + " had full memory and couldn't remember position of the new card. Trying with next player."); runs++; current++; if (current == totalPlayers){ current = 0;} } runs++; if(cards[x][y].value == (maxCard + 1)){ System.out.println("[FOUND]-- Player " + (current + 1) + " found card with value " + cards[x][y].value + " on [" + x + ";" + y + "]"); maxCard++;} else {System.out.println("[NEW]---- Player " + (current + 1) + " remembered card on [" + x + ";" + y + "]. Value of the card is " + cards[x][y].value);} x++; if (x >= 3){x=0;y++;} if (y >= 5){y=0;} } System.out.println("[RESULT]- " + runs + " runs were needed."); System.out.println(); } }

Summer camp competition