Question

USING RECURSIONN!!! JAVA CODE

Coin game: Alice and Bob are playing a game using a bunch of coins. The players
pick several coins out of the bunch in turn. Each time a player is allowed to pick 1, 2 or 4
coins, and the player that gets the last coin is the winner. Assume that both players are
very smart and he/she will try his/her best to work out a strategy to win the game. For
example, if there are 2 coins and Alice is the rst player to pick, she will denitely pick 2
coins and win. If there are 3 coins and Alice is still the rst player to pick, no matter she
picks 1 or 2 coins, Bob will get the last coin and win the game.
Given the number of coins and the order of players (which means the rst and the second
players to pick the coins), you are required to write a program pickcoin.java to calculate
the winner of the game, and calculate how many different strategies there are for he/she
to win the game. You should use recursion to solve the problem, and the parameters are
read from the command line. You can assume that there are no more than 35 coins.

Answer 1

Code:

public class CoinGame
{
public static void Count(int n, String[] s) // n: no. of coins
//s:{"Alice","Bob"} (order)
{
if(n>0)
{
if(n==1 || n==2 || n==4) System.out.println( s[0] ); // if 1/2/4
//coins left, the one with first chance wins
else
{
Count(n-1,new String[]{s[1],s[0]});
Count(n-2,new String[]{s[1],s[0]});
Count(n-4,new String[]{s[1],s[0]});
}
}
}

public static void main(String[] args)
{
String[] order = new String[]{"Alice","Bob"};
Count(5,order);
}
}
Output: