Below text is from binomial queues article.
Although both leftist and skew heaps support merging, insertion, and
delete_min all effectively in O(log n) time per operation, there is
room for improvement because we know that binary heaps support
insertion in constant average time per operation. Binomial queues
support all three operations in O(log n) worst-case time per
operation, but insertions take constant time on average.
In above text what does author mean by constant average time per operation? and how it is different from for binomial queues insertion takes constant
time on average?
What is difference between constant average time per operation and constant time on average?
There is no difference. The author is contrasting leftist and skew heaps on the one hand, and binary heaps on the other, to show that binomial heaps have some of the advantages of binary heaps (expected O(1) insert) that leftist and skew heaps do not have (they only have amortized O(1) insert).