Need the actual logic of beelow problem

Hi everyone I couldn't find the actual logic behind below two problems:

Code:

(1) how to capture number of occurrences of 3 between 1 to 100? and 
(2) assigns a function to a pointer and subsequently call it.

all problems are in c++

As I'm new in this field so,please help me to sweep out the problems.
Thanks and regards
sdmahapatra

 

For 1st program you can go like this, check for the number. for example say number is 53...so check for each numbr, first 5 and then 3.