HDU5088(高斯消元)

Revenge of Nim II

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 443    Accepted Submission(s): 157


Problem Description
Nim is a mathematical game of strategy in which two players take turns removing objects from distinct heaps. On each turn, a player must remove at least one object, and may remove any number of objects provided they all come from the same heap.
---Wikipedia

Today, Nim takes revenge on you, again. As you know, the rule of Nim game is rather unfair, only the nim-sum (⊕) of the sizes of the heaps is zero will the first player lose. To ensure the fairness of the game, the second player has a chance to move some (can be zero) heaps before the game starts, but he has to move one heap entirely, i.e. not partially. Of course, he can’t move all heaps out, at least one heap should be left for playing. Will the second player have the chance to win this time?
 

Input
The first line contains a single integer T, indicating the number of test cases. 

Each test case begins with an integer N, indicating the number of heaps. Then N integer Ai follows, indicating the number of each heap.

[Technical Specification]
1. 1 <= T <= 100
2. 1 <= N <= 1 000
3. 1 <= Ai <= 1 000 000 000 000
 

Output
For each test case, output “Yes” if the second player can win by moving some (can be zero) heaps out, otherwise “No”.
 

Sample Input
3 1 2 3 2 2 2 5 1 2 3 4 5
 

Sample Output
No Yes Yes
Hint
For the third test case, the second player can move heaps with 4 and 5 objects out, so the nim-sum of the sizes of the left heaps is 1⊕2⊕3 = 0.

題意:RT

思路:將每個數的每一位看成列,n個數看成n行,由於數值是<=1e12的,所以最多也就40列,如果行數大於40,那麼一定可以用高斯消元得到至少有兩個數是相等的(一個數是0也行)

            如果n<=40那麼直接高斯消元求解即可

#include 
#include 
#include 
#include 
#include 
using namespace std;

typedef __int64 ll;
const int MAXN = 1010;
ll a[MAXN];
int n;

int gauss()
{
    if(n==1)return 0;
    for(int i=0;i40){
            printf("Yes\n");
            continue;
        }
        if(gauss())printf("Yes\n");
        else printf("No\n");
    }
    return 0;
}
發表評論
所有評論
還沒有人評論,想成為第一個評論的人麼? 請在上方評論欄輸入並且點擊發布.
相關文章