hdu-1907 John
题目链接:
http://acm.hdu.edu.cn/showproblem.php?pid=1907
题目类型:
博弈
题意描述:
有N个装有若干个糖果的盒子,有两个人轮流取盒子中的糖果,每次只能从一个盒子中拿不少于1个糖果(可以一次性取完)直到所有糖果都取完,最后一次取糖果的人输,问john是胜是负。
解题思路:
该题是nim博弈的变形,先进行一次判断是否所有的盒子中全都是1个糖果,如果这样,结果已定,如果不是,则对每一堆糖果的个数进行异或运算,如果最终值为0,则John输,反之则John胜。
题目:
John
Time Limit: 5000/1000 MS (Java/Others) Memory Limit: 65535/32768 K (Java/Others)
Total Submission(s): 4816 Accepted Submission(s): 2780
Problem Description
Little John is playing very funny game with his younger brother. There is one big box filled with M&Ms of different colors. At first John has to eat several M&Ms of the same color. Then his opponent has to make a turn. And so on. Please note that each player has to eat at least one M&M during his turn. If John (or his brother) will eat the last M&M from the box he will be considered as a looser and he will have to buy a new candy box.
Both of players are using optimal game strategy. John starts first always. You will be given information about M&Ms and your task is to determine a winner of such a beautiful game.
Both of players are using optimal game strategy. John starts first always. You will be given information about M&Ms and your task is to determine a winner of such a beautiful game.
Input
The first line of input will contain a single integer T – the number of test cases. Next T pairs of lines will describe tests in a following format. The first line of each test will contain an integer N – the amount of different M&M colors in a box. Next line will contain N integers Ai, separated by spaces – amount of M&Ms of i-th color.
Constraints:
1 <= T <= 474,
1 <= N <= 47,
1 <= Ai <= 4747
Constraints:
1 <= T <= 474,
1 <= N <= 47,
1 <= Ai <= 4747
Output
Output T lines each of them containing information about game winner. Print “John” if John will win the game or “Brother” in other case.
Sample Input
2
3
3 5 1
1
1
Sample Output
John
Brother
# include <stdio.h> int game(int a[],int n) { int i,num,ret; ret=0; for(i=0;i<n;i++) if(a[i]!=1) ret=1; if(ret==0) { if(n%2==0) return 1; else return 0; } num=0; for(i=0;i<n;i++) num=num^a[i]; if(num!=0) return 1; else return 0; } int main () { int t,n,i,a[50]; scanf("%d",&t); while(t--) { scanf("%d",&n); for(i=0;i<n;i++) scanf("%d",&a[i]); if(game(a,n)==1) printf("John\n"); else printf("Brother\n"); } return 0; }