Balls and Boxes

Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/65536 K (Java/Others)

Total Submission(s): 798 Accepted Submission(s): 527

Problem Description

Mr. Chopsticks is interested in random phenomena, and he conducts an experiment to study randomness. In the experiment, he throws n balls into m boxes in such a manner that each ball has equal probability of going to each boxes. After the experiment, he calculated the statistical variance V as

V = \sum m i = 1 ( X i - X ¯ ) 2 m

Input

The input contains multiple test cases. Each case contains two integers n and m (1 <= n, m <= 1000 000 000) in a line.

The input is terminated by n = m = 0.

Output

For each case, output the result as A/B in a line, where A/B should be an irreducible fraction. Let B=1 if the result is an integer.

Sample Input

2 1

2 2

0 0

Sample Output

0/1

1/2

Hint

In the second sample, there are four possible outcomes, two outcomes with V = 0 and two outcomes with V = 1.

Author

SYSU

Source

题解：

转自：http://blog.csdn.net/qq978874169/article/details/52165136

#include
      
       #include
       
        #include
        
         using namespace std;typedef long long int ll;ll n,m;ll fenzi,fenmu;ll tmp;ll gcd(ll a,ll b){    return b==0?a:gcd(b,a%b);}int main(){    while(~scanf("%lld%lld",&n,&m)&&(n*m))    {        fenzi=n*(m-1);        fenmu=m*m;        tmp=gcd(fenzi,fenmu);        fenzi/=tmp;        fenmu/=tmp;        printf("%lld/%lld\n",fenzi,fenmu);    }    return 0;}

转载于:https://www.cnblogs.com/stepping/p/7169700.html

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