I was reading some sorting algorithm here (http://www.sorting-algorithms.com/insertion-sort) and i saw following line
i = 2:n
Can someone explains what does this mean ?
Theoretically I understand that for insertion sort i = size of array. But can someone tell me if i am getting it right ?
This notation is often used to describe ranges of numbers. In your case for i = 2:n can be read as "for every i in numbers 2 to n". If n=4, the loop will run three times with i = 2, i = 3, and i = 4.
In the pseudocode on the site you linked:
for i = 2:n,
for (k = i; k > 1 and a[k] < a[k-1]; k--)
swap a[k,k-1]
end
The first line means that the second and third lines are repeated n-1 times, and the first time, i = 2, the second time, i = 3, the third time, i = 4, and the last time i = n.
It's basically a loop, similar to
for(int i = 2 ; i <= n ; i++)
Wherea n is defined somewhere above the loop.
Basically: Let i be 2, increment it until it reaches n and use i for each iteration to do some behaviour.
It means iteration with i taking values from 2 to n.
i = 2:nwould meaniis either an integer>= 2, but in this contexts more likely: a range / array from 2 to some higher numbern.n, but I'm not 100% sure.