[Interview Questions] use the least number of comparisons to find the maximum and secondary values in an array.

Description

Such as the question and no repeated Elements

The idea is to use the divide and conquer method to divide the array into two groups. The two groups respectively use the two comparison elimination methods to find their respective maximum values (a total of N-1 comparisons). The final two maximum values are compared, the larger one is the maximum value, and the second largest value is generated between the smaller one and all elements that have been compared with the maximum value (a total of log_2 N-1. You only need to use the smaller one.
And log_2 N-1 compared with the maximum value respectively (here we need to compare log_2 n-1 times) on the line. So the final number of comparisons is (logn + N-2 ).