Write an algorithm for searching a key from a sorted list using binary search technique
1. if (low > high)
2. return (-1)
3. mid = (low +high)/2;
4 .if ( X = = a [mid])
5 return (mid);
6 if ( X < a [mid])
7 search for X in a (low) to [mid -1];
8 else
9 search for X in a [mid + 1] to a [high];