Coins in a Line


There are n coins in a line. Two players take turns to take one or two coins from right side until there are no more coins left. The player who take the last coin wins.

Could you please decide the first play will win or lose?


n = 1, return true.

n = 2, return true.

n = 3, return false.

n = 4, return true.

n = 5, return true.


O(n) time and O(1) memory

Code - Java

public class Solution {
     * @param n: an integer
     * @return: a boolean which equals to true if the first player will win
    public boolean firstWillWin(int n) {
        if (n % 3 == 0) return false;
        return true;