Thread: Running time question.

Hi,
I have an array A of n integers, sorted from min to max, and two numbers a<=b, which are known to be in A. I would like to write a pseudo-code for a procedure whose running time is c1+c2log(n) and which returns the number of elements in A which satisfy a<=A[i]<=b.
I wrote the following but am not sure it satisfies the requirement for the running time and would appreciate some help:
*NB <- denotes an arrow*

Code:

Range(Input: integer n, sorted array A, integer a, integer b){
max  <-  n
i<-BinarySearch(n,A,a)
num  <-  1
while (A[i]<=b and i<=max){
    i  <-  i+1
    num  <-  num+1
}
output(num)
}

where BinarySearch is defined thus:

Code:

BinarySearch(Input: integer n, sorted array of integers A, integer x) { 
 min  <-  1, max  <-  n, found  <-  FALSE 
 while ( found = FALSE and min <= max ) { 
 mid  <-  |_(min + max) / 2_| 
 if (A[mid] = x) 
 found  <-  TRUE 
 else if (x < A[mid]) 
 max  <-  mid-1 
 else 
 min  <-  mid+1 
 } 
 if (found = TRUE) 
 output(mid) 
 else 
 output(NOT-FOUND) 
}