对分查找、欧几里得算法求最大公约数

对分查找

 1 int BinarySearch(const int A[], int x, int N)
 2 {
 3    int low, mid, high;
 4    low = 0, high = N - 1;
 5    while(low <= high)
 6    {
 7       mid = (low + high) / 2;
 8       if(A[mid] < x)
 9          low = mid + 1;
10       else
11          if(A[mid] > x)
12          high = mid - 1;
13       else
14          return mid;
15    }
16    return NotFound;
17 }

欧几里得算法求最大公因数：

 1 unsigned Gcd(unsigned int M, unsigned int N)
 2 {
 3    unsigned int Rem;
 4    while(N > 0)
 5    {
 6       Rem = M % N;
 7       M = N;
 8       N = Rem;
 9    }
10    return M;
11 }