2013
11-10

# Matches Game

Here is a simple game. In this game, there are several piles of matches and two players. The two player play in turn. In each turn, one can choose a pile and take away arbitrary number of matches from the pile (Of course the number of matches, which is taken away, cannot be zero and cannot be larger than the number of matches in the chosen pile). If after a player’s turn, there is no match left, the player is the winner. Suppose that the two players are all very clear. Your job is to tell whether the player who plays first can win the game or not.

The input consists of several lines, and in each line there is a test case. At the beginning of a line, there is an integer M (1 <= M <=20), which is the number of piles. Then comes M positive integers, which are not larger than 10000000. These M integers represent the number of matches in each pile.

For each test case, output “Yes” in a single line, if the player who play first will win, otherwise output “No”.

2 45 45
3 3 6 9


No
Yes


import java.util.Scanner;

public class Main {

public static void main(String[] args) {
Scanner cin = new Scanner(System.in);
while(true) {
int n = cin.nextInt();
int i = 0;
int[] a = new int[n];
while(n > 0) {
a[i++] = cin.nextInt();
n--;
}
for(i=1 ; i< a.length; i++)
a[i]=a[i]^a[i-1];
if(a[a.length-1] != 0)
System.out.println("Yes");
else
System.out.println("No");
}

}

}

1. 我没看懂题目
2
5 6 -1 5 4 -7
7 0 6 -1 1 -6 7 -5
我觉得第一个应该是5 6 -1 5 4 输出是19 5 4
第二个是7 0 6 -1 1 -6 7输出是14 7 7
不知道题目例子是怎么得出来的