Performance impact of realloc ()

Question

I have a list of records, at the starting I dont know the number of records. I need to read them into array. so is it advisable to read all record one by one & doing reallo

Answer 1

A realloc isn't really very expensive. But calling realloc for each element is a bit much. I suggest you do this:

• Start with a size
• When you add an element, check if you have enough space
• When you don't have enough space, double the currrent amount

Correctly guessing an adequate initial size also helps. So if 60% of your inputs are less than 100 records, start with that.