As per the example given in this MIT OCW link URL https://ocw.mit.edu/courses/civil-and-environmental-engineering/1-124j-foundations-of-software-engineering-fall-2000/lecture-notes/sorting/
Why selection sort requires $O(N)$ time since the number of exchanges is at most N. Pls give example algorithm that prove this fact. Below is excerpt taken from same MIT OCW URL for reference
Selection sort is easy to implement; there is little that can go wrong with it. However, the method requires $O(N^2)$ comparisons and so it should only be used on small files. There is an important exception to this rule. When sorting files with large records and small keys, the cost of exchanging records controls the running time. In such cases, selection sort requires $O(N)$ time since the number of exchanges is at most $N$.