UVa 12068 - Harmonic Mean

Accepted date: 2015-07-31
Ranking (as of 2015-07-31): 16 out of 634
Language: C++

/*
  UVa 12068 - Harmonic Mean

  To build using Visual Studio 2012:
    cl -EHsc -O2 UVa_12068_Harmonic_Mean.cpp
*/

#include <cstdio>

long long gcd(long long x, long long y)
{
  if (x < y)
    return gcd(y, x);
  else
      return y == 0 ? x : gcd(y, x % y);
}

int main()
{
  int S;
  scanf("%d", &S);
  for (int s = 1; s <= S; s++) {
    const int N_max = 8;
    int N, numbers[N_max];
    scanf("%d", &N);
    for (int i = 0; i < N; i++)
      scanf("%d", &numbers[i]);
    long long numerator = N, denominator = 0;
    for (int i = 0; i < N; i++) {
      numerator *= numbers[i];
      long long d = 1;
      for (int j = 0; j < N - 1; j++)
        d *= numbers[(i + j) % N];
      denominator += d;
    }
    long long g = gcd(numerator, denominator);
    printf("Case %d: %lld/%lld\n", s, numerator / g, denominator / g);
  }
  return 0;
}